Intranasal Delivery of Genistein-Loaded Nanoparticles as a Potential Preventive System against Neurodegenerative Disorders

Genistein transfersome-embedded topical delivery system for skin melanoma treatment: in vitro and ex vivo evaluations

Skin melanoma is considered the most dangerous form of skin cancer due to its association with high risk of metastasis, high mortality rate and high resistance to different treatment options. Genistein is a natural isoflavonoid with known chemotherapeutic activity. Unfortunately, it has low bioavailability due to its poor aqueous solubility and excessive metabolism. In the current study, genistein was incorporated into transferosomal hydrogel to improve its bioavailability. The prepared transferosomal formulations were characterized regarding: particle size; polydispersity index; zeta potential; encapsulation efficiency; TEM; FTIR; DSC; XRD; in vitro drug release; viscosity; pH; ex vivo anti-tumor activity on 3D skin melanoma spheroids and 1-year stability study at different storage temperatures. The optimized formulation has high encapsulation efficiency with an excellent particle size that will facilitate its penetration through the skin. The transfersomes have a spherical shape with sustained drug release profile. The anti-tumor activity evaluation of genistein transfersome revealed that genistein is a potent chemotherapeutic agent with enhanced penetration ability through the melanoma spheroids when incorporated into transfersomes. Stability study results demonstrate the high physical and chemical stability of our formulations. All these outcomes provide evidence that our genistein transferosomal hydrogel is a promising treatment option for skin melanoma.

Underlying mechanisms and molecular targets of genistein in the management of type 2 diabetes mellitus and related complications

Diabetes mellitus (DM) is a chronic metabolic disease caused by a complex interaction of genetic and environmental factors and is characterized by persistent hyperglycemia. Long-term hyperglycemia can cause macrovascular and microvascular damage, and compromise the heart, brain, kidney, peripheral nerves, eyes and other organs, leading to serious complications. Genistein, a phytoestrogen derived from soybean, is known for its various biological activities and therapeutic properties. Recent studies found that genistein not only has hypoglycemic activity but can also decrease insulin resistance. In addition, genistein has particular activity in the prevention and treatment of diabetic complications, such as nephropathy, cardiovascular disease, osteoarthrosis, encephalopathy and retinopathy. Therefore, the purpose of this review is to summarize the latest medical research and progress of genistein in DM and related complications and highlights its potential molecular mechanisms and therapeutic targets. Meanwhile, evidence is provided for the development and application of genistein as a potential drug or functional food in the prevention and treatment of diabetes and its related complications.

Epigallocatechin-3-Gallate and Genistein for Decreasing Gut Dysbiosis, Inhibiting Inflammasomes, and Aiding Autophagy in Alzheimer's Disease

There are approximately 24 million cases of Alzheimer's disease (AD) worldwide, and the number of cases is expected to increase four-fold by 2050. AD is a neurodegenerative disease that leads to severe dementia in most patients. There are several neuropathological signs of AD, such as deposition of amyloid beta (Aβ) plaques, formation of neurofibrillary tangles (NFTs), neuronal loss, activation of inflammasomes, and declining autophagy. Several of these hallmarks are linked to the gut microbiome. The gastrointestinal (GI) tract contains microbial diversity, which is important in regulating several functions in the brain via the gut-brain axis (GBA). The disruption of the balance in the gut microbiota is known as gut dysbiosis. Recent studies strongly support that targeting gut dysbiosis with selective bioflavonoids is a highly plausible solution to attenuate activation of inflammasomes (contributing to neuroinflammation) and resume autophagy (a cellular mechanism for lysosomal degradation of the damaged components and recycling of building blocks) to stop AD pathogenesis. This review is focused on two bioflavonoids, specifically epigallocatechin-3-gallate (EGCG) and genistein (GS), as a possible new paradigm of treatment for maintaining healthy gut microbiota in AD due to their implications in modulating crucial AD signaling pathways. The combination of EGCG and GS has a higher potential than either agent alone to attenuate the signaling pathways implicated in AD pathogenesis. The effects of EGCG and GS on altering gut microbiota and GBA were also explored, along with conclusions from various delivery methods to increase the bioavailability of these bioflavonoids in the body.

Articulating the Pharmacological and Nanotechnological Aspects of Genistein: Current and Future Prospectives

Throughout the past several centuries, herbal constituents have been the subject of scientific interest and the latest research into their therapeutic potential is underway. Genistein is a soy-derived isoflavone found in huge amounts in soy, along with the plants of the Fabaceae family. Scientific studies have demonstrated the beneficial effects of genistein on various health conditions. Genistein presents a broad range of pharmacological activities, including anticancer, neuroprotective, cardioprotective, antiulcer, anti-diabetic, wound healing, anti-bacterial, antiviral, skin, and radioprotective effects. However, the hydrophobic nature of genistein results in constrained absorption and restricts its therapeutic potential. In this review, the number of nanocarriers for genistein delivery has been explored, such as polymeric nanoparticles, nanostructured lipid carriers, solid lipid nanoparticles, liposomes, micelles, transferosomes, and nanoemulsions and nanofibers. These nano-formulations of genistein have been utilized as a potential strategy for various disorders, employing a variety of ex vivo, in vitro, and in vivo models and various administration routes. This review concluded that genistein is a potential therapeutic agent for treating various diseases, including cancer, neurodegenerative disorders, cardiovascular disorders, obesity, diabetes, ulcers, etc., when formulated in suitable nanocarriers.

Drug Target to Alleviate Mitochondrial Dysfunctions in Alzheimer's Disease: Recent Advances and Therapeutic Implications

Alzheimer's disease (AD) is a severe progressive neurodegenerative condition associated with neuronal damage and reduced cognitive function that primarily affects the aged worldwide. While there is increasing evidence suggesting that mitochondrial dysfunction is one of the most significant factors contributing to AD, its accurate pathobiology remains unclear. Mitochondrial bioenergetics and homeostasis are impaired and defected during AD pathogenesis. However, the potential of mutations in nuclear or mitochondrial DNA encoding mitochondrial constituents to cause mitochondrial dysfunction has been considered since it is one of the intracellular processes commonly compromised in early AD stages. Additionally, electron transport chain dysfunction and mitochondrial pathological protein interactions are related to mitochondrial dysfunction in AD. Many mitochondrial parameters decline during aging, causing an imbalance in reactive oxygen species (ROS) production, leading to oxidative stress in age-related AD. Moreover, neuroinflammation is another potential causative factor in AD-associated mitochondrial dysfunction. While several treatments targeting mitochondrial dysfunction have undergone preclinical studies, few have been successful in clinical trials. Therefore, this review discusses the molecular mechanisms and different therapeutic approaches for correcting mitochondrial dysfunction in AD, which have the potential to advance the future development of novel drug-based AD interventions.

Regulation of neuroinflammation in Alzheimer's disease via nanoparticle-loaded phytocompounds with anti-inflammatory and autophagy-inducing properties

BACKGROUND

Alzheimer's disease (AD) is characterized by neuroinflammation linked to amyloid β (Aβ) aggregation and phosphorylated tau (τ) protein in neurofibrillary tangles (NFTs). Key elements in Aβ production and NFT assembly, like γ-secretase and p38 mitogen-activated protein kinase (p38MAPK), contribute to neuroinflammation. In addition, impaired proteosomal and autophagic pathways increase Aβ and τ aggregation, leading to neuronal damage. Conventional neuroinflammation drugs have limitations due to unidirectional therapeutic approaches and challenges in crossing the Blood-Brain Barrier (BBB). Clinical trials for non-steroidal anti-inflammatory drugs (NSAIDs) and other therapeutics remain uncertain. Novel strategies addressing the complex pathogenesis and BBB translocation are needed to effectively tackle AD-related neuroinflammation.

PURPOSE

The current scenario demands for a much-sophisticated theranostic measures which could be achieved via customized engineering and designing of novel nanotherapeutics. As, these therapeutics functions as a double edge sword, having the efficiency of unambiguous targeting, multiple drug delivery and ability to cross BBB proficiently.

METHODS

Inclusion criteria involve selecting recent, English-language studies from the past decade (2013-2023) that explore the regulation of neuroinflammation in neuroinflammation, Alzheimer's disease, amyloid β, tau protein, nanoparticles, autophagy, and phytocompounds. Various study types, including clinical trials, experiments, and reviews, were considered. Exclusion criteria comprised non-relevant publication types, studies unrelated to Alzheimer's disease or phytocompounds, those with methodological flaws, duplicates, and studies with inaccessible data.

RESULTS

In this study, polymeric nanoparticles loaded with specific phytocompounds and coated with an antibody targeting the transferrin receptor (anti-TfR) present on BBB. Thereafter, the engineered nanoparticles with the ability to efficiently traverse the BBB and interact with target molecules within the brain, could induce autophagy, a cellular process crucial for neuronal health, and exhibit potent anti-inflammatory effects. Henceforth, the proposed combination of desired phytocompounds, polymeric nanoparticles, and anti-TfR coating presents a promising approach for targeted drug delivery to the brain, with potential implications in neuroinflammatory conditions such as Alzheimer's disease.

Microfluidic Synthesis of Ultrasmall Chitosan/Graphene Quantum Dots Particles for Intranasal Delivery in Alzheimer's Disease Treatment

Nanoparticles (NPs) based therapies for Alzheimer's disease (AD) attract interest due to their ability to pass across or bypass the blood-brain barrier. Chitosan (CS) NPs or graphene quantum dots (GQDs) are promising drug carriers with excellent physicochemical and electrical properties. The current study proposes the combination of CS and GQDs in ultrasmall NP form not as drug carriers but as theranostic agents for AD. The microfluidic-based synthesis of the CS/GQD NPs with optimized characteristics makes them ideal for transcellular transfer and brain targeting after intranasal (IN) delivery. The NPs have the ability to enter the cytoplasm of C6 glioma cells in vitro and show dose and time-dependent effects on the viability of the cells. IN administration of the NPs to streptozotocin (STZ) induced AD-like models lead to a significant number of entrances of the treated rats to the target arm in the radial arm water maze (RAWM) test. It shows the positive effect of the NPs on the memory recovery of the treated rats. The NPs are detectable in the brain via in vivo bioimaging due to GQDs as diagnostic markers. The noncytotoxic NPs localize in the myelinated axons of hippocampal neurons. They do not affect the clearance of amyloid β (Aβ) plaques at intercellular space. Moreover, they showed no positive impact on the enhancement of MAP2 and NeuN expression as markers of neural regeneration. The memory improvement in treated AD rats may be due to neuroprotection via the anti-inflammation effect and regulation of the brain tissue microenvironment that needs to be studied.

Nose-to-brain drug delivery for the treatment of CNS disease: New development and strategies

Delivering drugs to the brain has always been a challenging task due to the restrictive properties of the blood-brain barrier (BBB). Intranasal delivery is therefore emerging as an efficient method of administration, making it easy to self-administration and thus provides a non-invasive and painless alternative to oral and parenteral administration for delivering therapeutics to the central nervous system (CNS). Recently, drug formulations have been developed to further enhance this nose-to-brain transport, primarily using nanoparticles (NPs). Therefore, the purposes of this review are to highlight and describe the anatomical basis of nasal-brain pathway and provide an overview of drug formulations and current drugs for intranasal administration in CNS disease.

Green Routes for Bio-Fabrication in Biomedical and Pharmaceutical Applications

In the last decade, significant advances in nanotechnologies, rising from increasing knowledge and refining of technical practices in green chemistry and bioengineering, enabled the design of innovative devices suitable for different biomedical applications. In particular, novel bio-sustainable methodologies are developing to fabricate drug delivery systems able to sagely mix properties of materials (i.e., biocompatibility, biodegradability) and bioactive molecules (i.e., bioavailability, selectivity, chemical stability), as a function of the current demands for the health market. The present work aims to provide an overview of recent developments in the bio-fabrication methods for designing innovative green platforms, emphasizing the relevant impact on current and future biomedical and pharmaceutical applications.

Nose-to-Brain Targeting via Nanoemulsion: Significance and Evidence

Background: Non-invasive and patient-friendly nose-to-brain pathway is the best-suited route for brain delivery of therapeutics as it bypasses the blood–brain barrier. The intranasal pathway (olfactory and trigeminal nerves) allows the entry of various bioactive agents, delivers a wide array of hydrophilic and hydrophobic drugs, and circumvents the hepatic first-pass effect, thus targeting neurological diseases in both humans and animals. The olfactory and trigeminal nerves make a bridge between the highly vascularised nasal cavity and brain tissues for the permeation and distribution, thus presenting a direct pathway for the entry of therapeutics into the brain. Materials: This review portrays insight into recent research reports (spanning the last five years) on the nanoemulsions developed for nose-to-brain delivery of actives for the management of a myriad of neurological disorders, namely, Parkinson’s disease, Alzheimer’s, epilepsy, depression, schizophrenia, cerebral ischemia and brain tumours. The information and data are collected and compiled from more than one hundred Scopus- and PubMed-indexed articles. Conclusions: The olfactory and trigeminal pathways facilitate better biodistribution and bypass BBB issues and, thus, pose as a possible alternative route for the delivery of hydrophobic, poor absorption and enzyme degradative therapeutics. Exploring these virtues, intranasal nanoemulsions have proven to be active, non-invasiveand safe brain-targeting cargos for the alleviation of the brain and other neurodegenerative disorders.

Nanoparticles loaded with pharmacologically active plant-derived natural products: Biomedical applications and toxicity

Pharmacologically active natural products have played a significant role in the history of drug development. They have acted as sources of therapeutic drugs for various diseases such as cancer and infectious diseases. However, most natural products suffer from poor water solubility and low bioavailability, limiting their clinical applications. The rapid development of nanotechnology has opened up new directions for applying natural products and numerous studies have explored the biomedical applications of nanomaterials loaded with natural products. This review covers the recent research on applying plant-derived natural products (PDNPs) nanomaterials, including nanomedicines loaded with flavonoids, non-flavonoid polyphenols, alkaloids, and quinones, especially their use in treating various diseases. Furthermore, some drugs derived from natural products can be toxic to the body, so the toxicity of them is discussed. This comprehensive review includes fundamental discoveries and exploratory advances in natural product-loaded nanomaterials that may be helpful for future clinical development.

Tailoring functional spray-dried powder platform for efficient donepezil nose-to-brain delivery

Shortcomings of oral donepezil administration in the treatment of Alzheimer's disease have paved the way for ongoing investigations towards more efficient and safe donepezil nose-to-brain delivery. Herein we present the development of advantageous powder platform for donepezil nose-to-brain delivery, coupling careful design of chitosan and mannitol-based carrier matrix with spray-drying technology advantages and early consideration of adequate nasal administration mode, employing QbD approach. Unprecedentedly, ultrasonic nozzle was used to atomise the drying feed in response to size-related requirements for nasal aerosol particles. The optimised spray-drying process resulted in free-flowable dry powder with a great majority of particles larger than 10 µm, ensuring localised nasal deposition upon aerosolization, as evidenced by using 3D-printed nasal cavity model. QbD approach coupling formulation, process and administration parameters enabled optimisation of drug deposition profile reaching tremendously high 65.5 % of the applied dose deposited in the olfactory region. The leading formulation exhibited favourable swelling, mucoadhesion, drug release and permeation-enhancing properties, suiting the needs for efficient brain-targeted delivery. Results of in vitro biocompatibility and physico-chemical stability studies confirmed the leading formulation potential for safe and efficient donepezil nose-to-brain delivery. The obtained results encourage extending the study to an appropriate in vivo model needed for the final proof-of-concept.

Micro- and Nanosized Carriers for Nose-to-Brain Drug Delivery in Neurodegenerative Disorders

Neurodegenerative disorders (NDs) have become a serious health problem worldwide due to the rapid increase in the number of people that are affected and the constantly aging population. Among all NDs, Alzheimer’s and Parkinson’s disease are the most common, and many efforts have been made in the development of effective and reliable therapeutic strategies. The intranasal route of drug administration offers numerous advantages, such as bypassing the blood–brain barrier and providing a direct entrance to the brain through the olfactory and trigeminal neurons. The present review summarizes the available information on recent advances in micro- and nanoscale nose-to-brain drug-delivery systems as a novel strategy for the treatment of Alzheimer’s and Parkinson’s disease. Specifically, polymer- and lipid-base micro- and nanoparticles have been studied as a feasible approach to increase the brain bioavailability of certain drugs. Furthermore, nanocomposites are discussed as a suitable formulation for administration into the nasal cavity.

Therapeutic potentials of genistein: New insights and perspectives

Genistein, a polyphenolic isoflavone compound found abundantly in soy or soy-based products, is widely consumed in the Asian population. Genistein has poor bioavailability, to overcome this problem many advanced nano-drug delivery carrier systems are designed to enhance its water solubility and stability. However, further research is required to develop more efficient bioavailability improvement strategies. Genistein is a phytoestrogen which has been associated with reducing the risk of cancer, cardiovascular disorders, and diabetes mellitus. This plant-based bioactive compound possesses numerous biological activities such as anti-oxidant, anti-inflammatory, anti-obesity, anti-cancer, cardioprotective, and anti-diabetic activities to treat various disease states. Genistein has been used as an active therapeutic agent in many medications. Moreover, several clinical trials are in the ongoing stage to develop more efficient treatment therapies, especially for cancer treatment. This article highlights the protective and therapeutic benefits of genistein in the treatment of different ailments, and more specifically elaborates on the anti-cancer potential of genistein regarding various types of cancers. PRACTICAL APPLICATIONS: Genistein possesses versatile biological activities, including anti-diabetic, anti-inflammatory, anti-oxidant, anti-obesity, and anti-angiogenic. The most studied activity is anti-cancer. Currently, a number of pre-clinical and clinical trials are being carried out on anti-neoplastic and cytotoxic activities of genistein to develop novel therapeutic agents with excellent anti-cancer potential for the treatment of various kinds of cancer. Moreover, many bioavailability enhancement strategies have been developed to improve the bioavailability of genistein. Genistein shows significant hypoglycemic effects alone or in combination with other anti-diabetic agents. Genistein in combination with other chemotherapeutic agents is used for the treatment of prostate, bone, colorectal, glioma, breast, and bladder cancer.

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.

Ionotropic Gelation-Based Synthesis of Chitosan-Metal Hybrid Nanoparticles Showing Combined Antimicrobial and Tissue Regenerative Activities

The treatment of skin wounds poses significant clinical challenges, including the risk of bacterial infection. In particular due to its antimicrobial and tissue regeneration abilities chitosan (a polymeric biomaterial obtained by the deacetylation of chitin) has received extensive attention for its effectiveness in promoting skin wound repair. On the other hand, due to their intrinsic characteristics, metal nanoparticles (e.g., silver (Ag), gold (Au) or iron oxide (Fe3O4)) have demonstrated therapeutic properties potentially useful in the field of skin care. Therefore, the combination of these two promising materials (chitosan plus metal oxide NPs) could permit the achievement of a promising nanohybrid with enhanced properties that could be applied in advanced skin treatment. In this work, we have optimized the synthesis protocol of chitosan/metal hybrid nanoparticles by means of a straightforward synthetic method, ionotropic gelation, which presents a wide set of advantages. The synthesized hybrid NPs have undergone to a full physicochemical characterization. After that, the in vitro antibacterial and tissue regenerative activities of the achieved hybrids have been assessed in comparison to their individual constituent. As result, we have demonstrated the synergistic antibacterial plus the tissue regeneration enhancement of these nanohybrids as a consequence of the fusion between chitosan and metallic nanoparticles, especially in the case of chitosan/Fe3O4 hybrid nanoparticles.

Intranasal Administration of Undifferentiated Oligodendrocyte Lineage Cells as a Potential Approach to Deliver Oligodendrocyte Precursor Cells into Brain

Oligodendrocyte precursor cell (OPC) migration is a mechanism involved in remyelination; these cells migrate from niches in the adult CNS. However, age and disease reduce the pool of OPCs; as a result, the remyelination capacity of the CNS decreases over time. Several experimental studies have introduced OPCs to the brain via direct injection or intrathecal administration. In this study, we used the nose-to brain pathway to deliver oligodendrocyte lineage cells (human oligodendroglioma (HOG) cells), which behave similarly to OPCs in vitro. To this end, we administered GFP-labelled HOG cells intranasally to experimental animals, which were subsequently euthanised at 30 or 60 days. Our results show that the intranasal route is a viable route to the CNS and that HOG cells administered intranasally migrate preferentially to niches of OPCs (clusters created during embryonic development and adult life). Our study provides evidence, albeit limited, that HOG cells either form clusters or adhere to clusters of OPCs in the brains of experimental animals.

Piperine-Loaded Glycyrrhizic Acid- and PLGA-Based Nanoparticles Modified with Transferrin for Antitumor : Piperine-Loaded Glycyrrhizic Acid- and PLGA-Based Nanoparticles

The purpose of this study was to enhance the antitumor effect of piperine by constructing the nanoparticles modified with transferrin (Tf-PIP-NPs) and evaluating their efficacy in vitro and in vivo. The Tf-PIP-NPs were prepared by the solvent evaporation method, and their properties were characterized. The effects of Tf-PIP-NPs on cytotoxicity, cell uptake, apoptosis, and mitochondrial membrane potential were evaluated in HepG2 cells, MDA-MB-231 cells, and 4T1 cells. In a 4T1 tumor-bearing mouse model, the antitumor efficacy of Tf-PIP-NPs was assessed in terms of tumor volumes, changes in body weight, HE staining, and immunohistochemical analysis. With a mean particle size of 112.2 ± 1.27 nm, the zeta potential of (- 28.0 ± 1.6 mV) Tf-PIP-NPs were rapidly internalized by tumor cells after 1 h through the transferrin receptor (TfR)-mediated endocytosis pathway, significantly inducing cellular apoptosis and mitochondrial membrane potential loss. Although Tf-PIP-NPs had no significant difference with PIP-NPs in tumor volume inhibition due to the presence of tumor microenvironment, it could significantly upregulate the expression of related pro-apoptotic proteins and induce tumor necrosis. We used the self-assembly properties of glycyrrhizic acid (GL) and polymer-PLGA to encapsulate piperine and modified with the transferrin, which provided a promising approach to improve the antitumor efficacy for anticarcinogen.

The Beneficial Role of Natural Endocrine Disruptors: Phytoestrogens in Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia with a growing incidence rate primarily among the elderly. It is a neurodegenerative, progressive disorder leading to significant cognitive loss. Despite numerous pieces of research, no cure for halting the disease has been discovered yet. Phytoestrogens are nonestradiol compounds classified as one of the endocrine-disrupting chemicals (EDCs), meaning that they can potentially disrupt hormonal balance and result in developmental and reproductive abnormalities. Importantly, phytoestrogens are structurally, chemically, and functionally akin to estrogens, which undoubtedly has the potential to be detrimental to the organism. What is intriguing, although classified as EDCs, phytoestrogens seem to have a beneficial influence on Alzheimer's disease symptoms and neuropathologies. They have been observed to act as antioxidants, improve visual-spatial memory, lower amyloid-beta production, and increase the growth, survival, and plasticity of brain cells. This review article is aimed at contributing to the collective understanding of the role of phytoestrogens in the prevention and treatment of Alzheimer's disease. Importantly, it underlines the fact that despite being EDCs, phytoestrogens and their use can be beneficial in the prevention of Alzheimer's disease.

Electrochemotherapy of Deep-Seated Tumors: State of Art and Perspectives as Possible "EPR Effect Enhancer" to Improve Cancer Nanomedicine Efficacy

Simple Summary

Electroporation-based therapies (reversible electroporation, irreversible electroporation, electrochemotherapy) are used for the selective treatment of deep-seated tumors. The combination of the structural modifications of the lipid bilayer of cell membranes, due to the application of electrical pulses in the targeted tissue, with the concomitant systemic (intravenous) administration of drugs can be considered as a sort of bridge between local-regional and systemic treatments. A possible further application of these techniques can be envisaged in their use as enhancers of the so-called “enhanced permeability and retention” effect. The intratumoral uptake of drug-loaded nanocarriers concomitant with the application of electric pulses in the target tumor is a new scenario worthy of attention and can represent a potential new frontier for drug delivery in oncology.

Abstract

Surgical resection is the gold standard for the treatment of many kinds of tumor, but its success depends on the early diagnosis and the absence of metastases. However, many deep-seated tumors (liver, pancreas, for example) are often unresectable at the time of diagnosis. Chemotherapies and radiotherapies are a second line for cancer treatment. The “enhanced permeability and retention” (EPR) effect is believed to play a fundamental role in the passive uptake of drug-loaded nanocarriers, for example polymeric nanoparticles, in deep-seated tumors. However, criticisms of the EPR effect were recently raised, particularly in advanced human cancers: obstructed blood vessels and suppressed blood flow determine a heterogeneity of the EPR effect, with negative consequences on nanocarrier accumulation, retention, and intratumoral distribution. Therefore, to improve the nanomedicine uptake, there is a strong need for “EPR enhancers”. Electrochemotherapy represents an important tool for the treatment of deep-seated tumors, usually combined with the systemic (intravenous) administration of anticancer drugs, such as bleomycin or cisplatin. A possible new strategy, worthy of investigation, could be the use of this technique as an “EPR enhancer” of a target tumor, combined with the intratumoral administration of drug-loaded nanoparticles. This is a general overview of the rational basis for which EP could be envisaged as an “EPR enhancer” in nanomedicine.

The importance of pre-formulation studies and of 3D-printed nasal casts in the success of a pharmaceutical product intended for nose-to-brain delivery

This review aims to cement three hot topics in drug delivery: (a) the pre-formulation of new products intended for nose-to-brain delivery; (b) the development of nasal casts for studying the efficacy of potential new nose-to-brain delivery systems at the early of their development (pre-formulation); (c) the use of 3D printing based on a wide variety of materials (transparent, biocompatible, flexible) providing an unprecedented fabrication tool towards personalized medicine by printing nasal cast on-demand based on CT scans of patients. This review intends to show the links between these three subjects. Indeed, the pathway selected to administrate the drug to the brain not only influence the formulation strategies to implement but also the design of the cast, to get the most convincing measures from it. Moreover, the design of the cast himself influences the choice of the 3D-printing technology, which, in its turn, bring more constraints to the nasal replica design. Consequently, the formulation of the drug, the cast preparation and its realisation should be thought of as a whole and not separately.

Essential Oil-Loaded NLC for Potential Intranasal Administration

Complementary and alternative medicines represent an interesting field of research on which worldwide academics are focusing many efforts. In particular, the possibility to exploit pharmaceutical technology strategies, such as the nanoencapsulation, for the delivery of essential oils is emerging as a promising strategy not only in Italy but also all over the world. The aim of this work was the development of nanostructured lipid carriers (NLC) for the delivery of essential oils (Lavandula, Mentha, and Rosmarinus) by intranasal administration, an interesting topic in which Italian contributions have recently increased. Essential oil-loaded NLC, projected as a possible add-on strategy in the treatment of neurodegenerative diseases, were characterized in comparison to control formulations prepared with Tegosoft CT and Neem oil. Homogeneous (polydispersity index, PDI < 0.2) nanoparticles with a small size (<200 nm) and good stability were obtained. Morphological and physical-chemical studies showed the formation of different structures depending on the nature of the liquid oil component. In particular, NLC prepared with Lavandula or Rosmarinus showed the formation of a more ordered structure with higher cytocompatibility on two cell lines, murine and human fibroblasts. Taken together, our preliminary results show that optimized positively charged NLC containing Lavandula or Rosmarinus can be proposed as a potential add-on strategy in the treatment of neurodegenerative diseases through intranasal administration, due to the well-known beneficial effects of essential oils and the mucoadhesive properties of NLC.

Nanotechnologies for intranasal drug delivery: an update of literature

Scientific research has focused its attention on finding an alternative route to systemic oral and parenteral administration, to overcome their usual drawbacks, such as hepatic first-pass which decreases drug bioavailability after oral administration, off-target effects, low patient compliance and low speed of onset of the pharmacological action in first-aid cases. Innovative drug delivery systems (DDS), mainly based on polymer and lipid biocompatible materials, have given a great prompt in this direction in the last years. The intranasal (IN) route of administration is a valid non-invasive alternative. It is highly suitable for self-administration, the drug quickly reaches the bloodstream, largely avoiding the first pass effect, and can also reach directly the brain bypassing BBB. Association of IN route with DDS can thus become a winning strategy for the controlled delivery of drugs, especially when a very quick effect is desired or needed. This review aims at analyzing the scientific literature regarding IN-DDS and their different ways of administration (systemic, topical, pulmonary, nose-to-brain). In particular, attention was devoted to polymer- and lipid-based micro- and nanocarriers, being the topic of most published articles in the last decade, but the whole plethora of colloidal DDS investigated in recent years for IN administration was presented.

Melatonin-Loaded Nanocarriers: New Horizons for Therapeutic Applications

The use of nanosized particles has emerged to facilitate selective applications in medicine. Drug-delivery systems represent novel opportunities to provide stricter, focused, and fine-tuned therapy, enhancing the therapeutic efficacy of chemical agents at the molecular level while reducing their toxic effects. Melatonin (N-acetyl-5-methoxytriptamine) is a small indoleamine secreted essentially by the pineal gland during darkness, but also produced by most cells in a non-circadian manner from which it is not released into the blood. Although the therapeutic promise of melatonin is indisputable, aspects regarding optimal dosage, biotransformation and metabolism, route and time of administration, and targeted therapy remain to be examined for proper treatment results. Recently, prolonged release of melatonin has shown greater efficacy and safety when combined with a nanostructured formulation. This review summarizes the role of melatonin incorporated into different nanocarriers (e.g., lipid-based vesicles, polymeric vesicles, non-ionic surfactant-based vesicles, charge carriers in graphene, electro spun nanofibers, silica-based carriers, metallic and non-metallic nanocomposites) as drug delivery system platforms or multilevel determinations in various in vivo and in vitro experimental conditions. Melatonin incorporated into nanosized materials exhibits superior effectiveness in multiple diseases and pathological processes than does free melatonin; thus, such information has functional significance for clinical intervention.

Crocetin as New Cross-Linker for Bioactive Sericin Nanoparticles

The nose-to-brain delivery route is used to bypass the blood–brain barrier and deliver drugs directly into the brain. Over the years, significant signs of progress have been made in developing nano-drug delivery systems to address the very low drug transfer levels seen with conventional formulations (e.g., nasal solutions). In this paper, sericin nanoparticles were prepared using crocetin as a new bioactive natural cross-linker (NPc) and compared to sericin nanoparticles prepared with glutaraldehyde (NPg). The mean diameter of NPc and NPg was about 248 and 225 nm, respectively, and suitable for nose-to-brain delivery. The morphological investigation revealed that NPc are spherical-like particles with a smooth surface, whereas NPg seem small and rough. NPc remained stable at 4 °C for 28 days, and when freeze-dried with 0.1% w/v of trehalose, the aggregation was prevented. The use of crocetin as a natural cross-linker significantly improved the in vitro ROS-scavenging ability of NPc with respect to NPg. Both formulations were cytocompatible at all the concentrations tested on human fibroblasts and Caco-2 cells and protected them against oxidative stress damage. In detail, for NPc, the concentration of 400 µg/mL resulted in the most promising to maintain the cell metabolic activity of fibroblasts higher than 90%. Overall, the results reported in this paper support the employment of NPc as a nose-to-brain drug delivery system, as the brain targeting of antioxidants is a potential tool for the therapy of neurological diseases.

Transmucosal Solid Lipid Nanoparticles to Improve Genistein Absorption via Intestinal Lymphatic Transport

Genistein (GEN) is a soy-derived isoflavone that exhibits several biological effects, such as neuroprotective activity and the prevention of several types of cancer and cardiovascular disease. However, due to its poor water solubility and the extensive first-pass metabolism, the oral bioavailability of GEN is limited. In this work, solid lipid nanoparticles (SLN) were developed to preferentially reach the intestinal lymphatic vessels, avoiding the first-pass metabolism of GEN. GEN-loaded SLN were obtained by a hot homogenization process, and the formulation parameters were chosen based on already formulated studies. The nanoparticles were characterized, and the preliminary in vitro chylomicron formation was evaluated. The cell uptake of selected nanocarriers was studied on the Caco-2 cell line and intestinal mucosa. The SLN, characterized by a spherical shape, showed an average diameter (about 280 nm) suitable for an intestinal lymphatic uptake, good stability during the testing time, and high drug loading capacity. Furthermore, the intestinal mucosa and Caco-2 cells were found to uptake SLN. The approximately two-fold increase in particle size suggested a possible interaction between SLN and the lipid components of chylomicrons like phospholipid; therefore, the results may support the potential for these SLN to improve oral GEN bioavailability via intestinal lymphatic absorption.

Role of Flavonoids in Neurodegenerative Diseases: Limitations and Future Perspectives

BACKGROUND

Flavonoids, a group of natural dietary polyphenols, are known for their beneficial effects on human health. By virtue of their various pharmacological effects, like anti-oxidative, antiinflammatory, anti-carcinogenic and neuroprotective effects, flavonoids have now become an important component of herbal supplements, pharmaceuticals, medicinals and cosmetics. There has been enormous literature supporting neuroprotective effect of flavonoids. Recently their efficacy in various neurodegenerative diseases, like Alzheimer's disease and Parkinson diseases, has received particular attention.

OBJECTIVE

The mechanism of flavanoids neuroprotection might include antioxidant, antiapoptotic, antineuroinflammatory and modulation of various cellular and intracellular targets. In in-vivo systems, before reaching to brain, they have to cross barriers like extensive first pass metabolism, intestinal barrier and ultimately blood brain barrier. Different flavonoids have varied pharmacokinetic characteristics, which affect their pharmacodynamic profile. Therefore, brain accessibility of flavonoids is still debatable.

METHODS

This review emphasized on current trends of research and development on flavonoids, especially in neurodegenerative diseases, possible challenges and strategies to encounter using novel drug delivery system.

RESULTS

Various flavonoids have elicited their therapeutic potential against neurodegenerative diseases, however by using nanotechnology and novel drug delivery systems, the bioavailability of favonoids could be enhanced.

CONCLUSION

This study bridges a significant opinion on medicinal chemistry, ethanopharmacology and new drug delivery research regarding use of flavonoids in management of neurodegeneration.

Potential Therapeutic Role of Phytochemicals to Mitigate Mitochondrial Dysfunctions in Alzheimer's Disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by a decline in cognitive function and neuronal damage. Although the precise pathobiology of AD remains elusive, accumulating evidence suggests that mitochondrial dysfunction is one of the underlying causes of AD. Mutations in mitochondrial or nuclear DNA that encode mitochondrial components may cause mitochondrial dysfunction. In particular, the dysfunction of electron transport chain complexes, along with the interactions of mitochondrial pathological proteins are associated with mitochondrial dysfunction in AD. Mitochondrial dysfunction causes an imbalance in the production of reactive oxygen species, leading to oxidative stress (OS) and vice versa. Neuroinflammation is another potential contributory factor that induces mitochondrial dysfunction. Phytochemicals or other natural compounds have the potential to scavenge oxygen free radicals and enhance cellular antioxidant defense systems, thereby protecting against OS-mediated cellular damage. Phytochemicals can also modulate other cellular processes, including autophagy and mitochondrial biogenesis. Therefore, pharmacological intervention via neuroprotective phytochemicals can be a potential strategy to combat mitochondrial dysfunction as well as AD. This review focuses on the role of phytochemicals in mitigating mitochondrial dysfunction in the pathogenesis of AD.

Nose-to-Brain Delivery of Antioxidants as a Potential Tool for the Therapy of Neurological Diseases

Oxidative stress has a key role in the pathogenesis of neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's diseases and can be an important cause of the damages in cerebral ischemia. Oxidative stress arises from high levels of reactive oxygen species (ROS). Consequently, on this rational base, antioxidants (many of natural origin) are proposed as potential drugs to prevent ROS noxious actions because they can protect the target tissues from the oxidative stress. However, the potential of antioxidants is limited, owing to the presence of the blood-brain barrier (BBB), which is difficult to cross with a consequent low bioavailability of the drug into the brain after systemic (intravenous, intraperitoneal, oral) administrations. One strategy to improve the delivery of antioxidants to the brain involves the use of the so-called nose-to-brain route, with the administration of the antioxidant in specific nasal formulations and its passage to the central nervous system (CNS) mainly through the olfactory nerve way. In the current literature, many examples show encouraging results in studies carried out in cell cultures and in animal models about the potential neuroprotective effects of antioxidants when administered through the nose. This review concerns the nose-to-brain route for the brain targeting of antioxidants as a potential tool for the therapy of neurological diseases.

The Inclusion of a Matrix Metalloproteinase-9 Responsive Sequence in Self-assembled Peptide-based Brain-Targeting Nanoparticles Improves the Efficiency of Nanoparticles Crossing the Blood-Brain Barrier at Elevated MMP-9 Levels

This study investigated whether the inclusion of a matrix metalloproteinase-9 (MMP-9) responsive sequence in self-assembled peptide-based brain-targeting nanoparticles (NPs) would enhance the blood-brain barrier (BBB) penetration when MMP-9 levels are elevated both in the brain and blood circulation. Brain-targeting peptides were conjugated at the N-terminus to MMP-9-responsive peptides, and these were conjugated at the N-terminus to lipid moiety (cholesteryl chloroformate or palmitic acid). Two constructs did not have MMP-9-responsive peptides. NPs were characterised for size, charge, critical micelle concentration, toxicity, blood compatibility, neural cell uptake, release profiles, and in vitro BBB permeability simulating normal or elevated MMP-9 levels. The inclusion of MMP-9-sensitive sequences did not improve the release of a model drug in the presence of active MMP-9 from NPs compared to distilled water. ¹⁹F NMR studies suggested the burial of MMP-9-sensitive sequences inside the NPs making them inaccessible to MMP-9. Only cholesterol-GGGCKAPETALC (responsive to MMP-9) NPs showed <5% haemolysis, <1 pg/mL release of IL-1β at 500 μg/mL from THP1 cells, with 70.75 ± 5.78% of NPs crossing the BBB at 24 h in presence of active MMP-9. In conclusion, brain-targeting NPs showed higher transport across the BBB model when MMP-9 levels were elevated and the brain-targeting ligand was responsive to MMP-9.

The Application of Mucoadhesive Chitosan Nanoparticles in Nasal Drug Delivery

Mucosal delivery of antigens can induce both humoral and cellular immune responses. Particularly, the nasal cavity is a strongly inductive site for mucosal immunity among several administration routes, as it is generally the first point of contact for inhaled antigens. However, the delivery of antigens to the nasal cavity has some disadvantages such as rapid clearance and disposition of inhaled materials. For these reasons, remarkable efforts have been made to develop antigen delivery systems which suit the nasal route. The use of nanoparticles as delivery vehicles enables protection of the antigen from degradation and sustains the release of the loaded antigen, eventually resulting in improved vaccine and/or drug efficacy. Chitosan, which exhibits low toxicity, biodegradability, good cost performance, and strong mucoadhesive properties, is a useful material for nanoparticles. The present review provides an overview of the mucosal immune response induced by nanoparticles, recent advances in the use of nanoparticles, and nasal delivery systems with chitosan nanoparticles.

Solid Lipid Nanoparticles as Formulative Strategy to Increase Oral Permeation of a Molecule Active in Multidrug-Resistant Tuberculosis Management

The role of mycobacterial efflux pumps in drug-resistant tuberculosis has been widely reported. Recently, a new compound, named SS13, has been synthesized, and its activity as a potential efflux inhibitor has been demonstrated. In this work, the chemical-physical properties of the SS13 were investigated; furthermore, a formulative study aimed to develop a formulation suitable for oral administration was performed. SS13 shows nonintrinsic antitubercular activity, but it increases the antitubercular activity of all the tested drugs on several strains. SS13 is insoluble in different simulated gastrointestinal media; thus, its oral absorption could be limited. Solid lipid nanoparticles (SLNs) were, therefore, developed by using two different lipids, Witepsol and/or Gelucire. Nanoparticles, having a particle size (range of 200-450 nm with regards to the formulation composition) suitable for intestinal absorption, are able to load SS13 and to improve its permeation through the intestinal mucosa compared to the pure compound. The cytotoxicity is influenced by the concentration of nanoparticles administered. These promising results support the potential application of these nanocarriers for increasing the oral permeation of SS13 in multidrug-resistant tuberculosis management.

Tailoring Midazolam-Loaded Chitosan Nanoparticulate Formulation for Enhanced Brain Delivery via Intranasal Route

In the present study, midazolam (MDZ)-loaded chitosan nanoparticle formulation was investigated for enhanced transport to the brain through the intranasal (IN) route. These days, IN MDZ is very much in demand for treating life-threatening seizure emergencies; therefore, its nanoparticle formulation was formulated in the present work because it could substantially improve its brain targeting via the IN route. MDZ-loaded chitosan nanoparticles (MDZ-CSNPs) were formulated and optimized by the ionic gelation method and then evaluated for particle size, particle size distribution (PDI), drug loading (DL), encapsulation efficiency (EE), and in vitro release as well as in vitro permeation. The concentration of MDZ in the brain after the intranasal administration of MDZ-CSNPs (C_max 423.41 ± 10.23 ng/mL, tmax 2 h, and area under the curve from 0 to 480 min (AUC_0-480) of 1920.87 ng.min/mL) was found to be comparatively higher to that achieved following intravenous (IV) administration of MDZ solution (C_max 245.44 ± 12.83 ng/mL, t_max 1 h, and AUC_0-480 1208.94 ng.min/mL) and IN administration of MDZ solution (C_max 211.67 ± 12.82, t_max 2 h, and AUC_0-480 1036.78 ng.min/mL). The brain–blood ratio of MDZ-CSNPs (IN) were significantly greater at all sampling time points when compared to that of MDZ solution (IV) and MDZ (IN), which indicate that direct nose-to-brain delivery by bypassing the blood–brain barrier demonstrates superiority in brain delivery. The drug-targeting efficiency (DTE%) as well as nose-to-brain direct transport percentage (DTP%) of MDZ-CSNPs (IN) was found to be comparatively higher than that for other formulations, suggesting better brain targeting potential. Thus, the obtained results demonstrated that IN MDZ-CSNP has come up as a promising approach, which exhibits tremendous potential to mark a new landscape for the treatment of status epilepticus.

Nose-to-brain Delivery of Natural Compounds for the Treatment of Central Nervous System Disorders

BACKGROUND

Several natural compounds have demonstrated potential for the treatment of central nervous system disorders such as ischemic cerebrovascular disease, glioblastoma, neuropathic pain, neurodegenerative diseases, multiple sclerosis and migraine. This is due to their well-known antioxidant, anti-inflammatory, neuroprotective, anti-tumor, anti-ischemic and analgesic properties. Nevertheless, many of these molecules have poor aqueous solubility, low bioavailability and extensive gastrointestinal and/or hepatic first-pass metabolism, leading to a quick elimination as well as low serum and tissue concentrations. Thus, the intranasal route emerged as a viable alternative to oral or parenteral administration, by enabling a direct transport into the brain through the olfactory and trigeminal nerves. With this approach, the blood-brain barrier is circumvented and peripheral exposure is reduced, thereby minimizing possible adverse effects.

OBJECTIVE

Herein, brain-targeting strategies for nose-to-brain delivery of natural compounds, including flavonoids, cannabinoids, essential oils and terpenes, will be reviewed and discussed. Brain and plasma pharmacokinetics of these molecules will be analyzed and related to their physicochemical characteristics and formulation properties.

CONCLUSION

Natural compounds constitute relevant alternatives for the treatment of brain diseases but often require loading into nanocarrier systems to reach the central nervous system in sufficient concentrations. Future challenges lie in a deeper characterization of their therapeutic mechanisms and in the development of effective, safe and brain-targeted delivery systems for their intranasal administration.

Development, optimisation and evaluation of chitosan nanoparticles of alendronate against Alzheimer's disease in intracerebroventricular streptozotocin model for brain delivery

The current study aimed to develop alendronate (ALN)-loaded chitosan nanoparticles (CS-ALN-NPs) for brain delivery via intranasal route. These CS-ALN-NPs reduced the peripheral side effects and released ALN directly to brain. These NPs were formulated through ionic gelation technique by mixing sodium tripolyphosphate (1.5 mg/ml) in ALN-CS (1.75 mg/ml) solution. CS-ALN-NPs attained 135.75 ± 5.80 nm, 0.21 ± 0.013, 23.8 ± 3.69 mV, 72.46 ± 0.879% and 30.92 ± 0.375% mean particle size, PDI, zeta potential, entrapment efficiency and loading capacity, respectively. Furthermore, the TEM and SEM analysis of CS-ALN-NPs, respectively, revealed the particle size in 200 nm range and spherical shape. The in vitro and ex vivo release profile revealed a sustained drug release through CS-ALN-NPs as compared to pure drug solution. Also these NPs acquired a high concentration in mice brain and better pharmacokinetic profile than ALN solution (intranasal) CS-ALN-NPs were then evaluated against intracerebroventricular-streptozotocin (ICV-STZ) induced Alzheimer's disease (AD)-like pathologies in mice. The intranasal CS-ALN-NP altered the ICV-STZ induced neurobehavioral, neurochemical and histopathological changes in mice. These effects were significant to those of ALN solution (intranasal). The neuroprotective potential of CS-ALN-NPs observed in ICV-STZ mice model of AD may be a promising brain-targeted delivery system for AD treatment along with further extensive exploration at both pre-clinical and clinical edge. HIGHLIGHTS CS-ALN-NPs were developed and optimised to overcome the poor pharmacokinetic profile and associated side effects of ALN CS-ALN-NPs showed particle size within 200 nm range as well as controlled and sustained release in in vitro release study These optimised NPs of ALN attained higher brain:blood ratio and better pharmacokinetic profile (Cmax, tmax, AUC) CS-ALN-NPs markedly altered ICV STZ induced impairment in cognitive functions of mice and changes in APP processing, neuroinflammatory cytokines and other biochemical parameters in mice hippocampus.

Flavonoid Nanoparticles: A Promising Approach for Cancer Therapy

Flavonoids, a ubiquitous group of naturally occurring polyphenolic compounds, have recently gained importance as anticancer agents. Unfortunately, due to low solubility, absorption, and rapid metabolism of dietary flavonoids, their anticancer potential is not sufficient. Nanocarriers can improve the bioavailability of flavonoids. In this review we aimed to evaluate studies on the anticancer activity of flavonoid nanoparticles. A review of English language articles published until 30 June 2020 was conducted, using PubMed (including MEDLINE), CINAHL Plus, Cochrane, and Web of Science data. Most studies determining the anticancer properties of flavonoid nanoparticles are preclinical. The potential anticancer activity focuses mainly on MCF-7 breast cancer cells, A549 lung cancer cells, HepG2 liver cancer cells, and melanoma cells. The flavonoid nanoparticles can also support the anti-tumour effect of drugs used in cancer therapy by enhancing the anti-tumour effect or reducing the systemic toxicity of drugs.

Nanosystems for the Encapsulation of Natural Products: The Case of Chitosan Biopolymer as a Matrix

Chitosan is a cationic natural polysaccharide, which has emerged as an increasingly interesting biomaterialover the past few years. It constitutes a novel perspective in drug delivery systems and nanocarriers' formulations due to its beneficial properties, including biocompatibility, biodegradability and low toxicity. The potentiality of chemical or enzymatic modifications of the biopolymer, as well as its complementary use with other polymers, further attract the scientific community, offering improved and combined properties in the final materials. As a result, chitosan has been extensively used as a matrix for the encapsulation of several valuable compounds. In this review article, the advantageous character of chitosan as a matrix for nanosystemsis presented, focusing on the encapsulation of natural products. A five-year literature review is attempted covering the use of chitosan and modified chitosan as matrices and coatings for the encapsulation of natural extracts, essential oils or pure naturally occurring bioactive compounds are discussed.

Nutraceuticals in the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe disease characterized by the loss and obstructive remodeling of the pulmonary arterial wall, causing a rise in pulmonary arterial pressure and pulmonary vascular resistance, which is responsible for right heart failure, functional decline, and death. Although many drugs are available for the treatment of this condition, it continues to be life-threatening, and its long-term treatment is expensive. On the other hand, many natural compounds present in food have beneficial effects on several cardiovascular conditions. Several studies have explored many of the potential beneficial effects of natural plant products on PAH. However, the mechanisms by which natural products, such as nutraceuticals, exert protective and therapeutic effects on PAH are not fully understood. In this review, we analyze the current knowledge on nutraceuticals and their potential use in the protection and treatment of PAH, as well as whether nutraceuticals could enhance the effects of drugs used in PAH through similar mechanisms.

Particles Containing Cells as a Strategy to Promote Remyelination in Patients With Multiple Sclerosis

The repair of demyelinated lesions is a key objective in multiple sclerosis research. Remyelination fundamentally depends on oligodendrocyte progenitor cells (OPC) reaching the lesion; this is influenced by numerous factors including age, disease progression time, inflammatory activity, and the pool of OPCs available, whether they be NG2 cells or cells derived from neural stem cells. Administering OPCs has been proposed as a potential cell therapy; however, these cells can only be administered directly. This article discusses the potential administration of OPCs encapsulated within hydrogel particles composed of biocompatible biomaterials, via the nose-to-brain pathway. We also discuss conditions for the indication of this therapy, and such related issues as the influence on endogenous remyelination, migration of OPCs to demyelinated areas, and the immune response, given the autoimmune nature of multiple sclerosis. Chitosan and derivatives constitute the most promising biomaterial for this purpose, although these issues must be addressed. In conclusion, this line of research may yield an alternative to the remyelinating drugs currently being studied.

Neuroinflammation in pathogenesis of Alzheimer's disease: Phytochemicals as potential therapeutics

Accumulation of neurotoxic forms of amyloid-β proteins in senile plaques and hyperphosphorylated tau proteins in neurofibrillary tangles is a well-known pathophysiological hallmark of Alzheimer's disease (AD). However, clinical trials with drugs targeting amyloid-β and tau have failed to demonstrate efficacy in treating AD. All currently FDA-approved anti-AD drugs have symptomatic effects only and are not able to cure this disease. This makes necessary to search for alternative therapeutic targets. Accumulating evidence suggests that systemic inflammation and related vascular dysfunction play important etiological roles in AD and precede its clinical manifestation. Therefore, novel therapeutic modalities targeted at these pathophysiological components of AD are intensively developed now. Phytochemicals such as resveratrol, curcumin, quercetin, genistein and catechins are promising anti-AD therapeutics due to their ability to affect major pathogenetic mechanisms of AD, including oxidative stress, neuroinflammation and mitochondrial dysfunction. The implementation of innovative approaches for phytochemical delivery, including the nanotechnology-based ones which enable to significantly enhance their oral bioavailability, would likely provide an opportunity to address many challenges of conventional anti-AD therapies. In this review, roles of inflammation and vascular dysregulation in AD are described and phytobioactive compound-based treatment strategies for AD are discussed.

Nose-to-Brain Delivery

Nose-to-brain delivery represents a big challenge. In fact there is a large number of neurological diseases that require therapies in which the drug must reach the brain, avoiding the difficulties due to the blood-brain barrier (BBB) and the problems connected with systemic administration, such as drug bioavailability and side-effects. For these reasons the development of nasal formulations able to deliver the drug directly into the brain is of increasing importance. This Editorial regards the contributions present in the Special Issue "Nose-to-Brain Delivery".

Stable Chitosan-Based Nanoparticles Using Polyphosphoric Acid or Hexametaphosphate for Tandem Ionotropic/Covalent Crosslinking and Subsequent Investigation as Novel Vehicles for Drug Delivery

Chitosan nanoparticles (NPs) are widely studied as vehicles for drug, protein, and gene delivery. However, lack of sufficient stability, particularly under physiological conditions, render chitosan NPs of limited pharmaceutical utility. The aim of this study is to produce stable chitosan NPs suitable for drug delivery applications. Chitosan was first grafted to phthalic or phenylsuccinic acids. Subsequently, polyphosphoric acid (PPA), hexametaphosphate (HMP), or tripolyphosphate (TPP) were used to achieve tandem ionotropic/covalently crosslinked chitosan NPs in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). Thermal and infrared traits confirmed phosphoramide bonds formation tying chitosan with the polyphosphate crosslinkers within NPs matrices. DLS and TEM size analysis indicated spherical NPs with size range of 120 to 350 nm. The generated NPs exhibited excellent stabilities under harsh pH, CaCl₂, and 10% FBS conditions. Interestingly, DLS, NPs stability and infrared data suggest HMP to reside within NPs cores, while TPP and PPA to act mainly as NPs surface crosslinkers. Drug loading and release studies using methylene blue (MB) and doxorubicin (DOX) drug models showed covalent PPA- and HMP-based NPs to have superior loading capacities compared to NPs based on unmodified chitosan, generated by ionotropic crosslinking only or covalently crosslinked by TPP. Doxorubicin-loaded NPs were of superior cytotoxic properties against MCF-7 cells compared to free doxorubicin. Specifically, DOX-loaded chitosan-phthalate polyphosphoric acid-crosslinked NPs exhibited 10-folds cytotoxicity enhancement compared to free DOX. The use of PPA and HMP to produce covalently-stabilized chitosan NPs is completely novel.

Facile nose-to-brain delivery of rotigotine-loaded polymer micelles thermosensitive hydrogels: In vitro characterization and in vivo behavior study

A rotigotine (ROT)-loaded polymer micelles thermosensitive gel (ROT-PM-TSG) delivery system was engineered to enhance the solubility of the drug, prolong the residence time, and increase the concentration of the drug in the brain tissue. First, ROT-loaded polymer micelles (ROT-PM) were tailored and optimized. The average particle size, encapsulation efficiency, and drug loading of the ROT-PM were (88.62 ± 1.47) nm, (93.5 ± 0.79) %, and (19.9 ± 0.60) %. The optimal ROT-PM-TSG formulation contained 22% P407 and 2% P188 with a gelation temperature of about 32.3 °C and a pH of 5.186. In vivo, the MRT of ROT-PM and ROT-PM-TSG nasal administration was 1.43 and 1.79 times extended than that of the intravenous. In comparison with the intravenous group, the distribution of ROT in olfactory bulb, cerebrum, cerebellum and striatum was 276.6%, 170.5%, 166.5% and 184.4%, respectively. In conclusion, the ROT-PM-TSG system has proven to be a potential application prospect as a ROT nose-to-brain delivery system.

Nanodelivery of Natural Antioxidants: An Anti-aging Perspective

The aging process is known to be associated with heightened oxidative stress and related systemic inflammation. Therefore, antioxidant supplementation is regarded as a promising strategy to combat aging and associated pathological conditions. Food-grade antioxidants from plant-derived extracts are the most common ingredients of these supplements. Phyto-bioactive compounds such as curcumin, resveratrol, catechins, quercetin are among the most commonly applied natural compounds used as potential modulators of the free radical-induced cellular damages. The therapeutic potential of these compounds is, however, restricted by their low bioavailability related to poor solubility, stability, and absorbance in gastrointestinal tract. Recently, novel nanotechnology-based systems were developed for therapeutic delivery of natural antioxidants with improved bioavailability and, consequently, efficacy in clinical practice. Such systems have provided many benefits in preclinical research over the conventional preparations, including superior solubility and stability, extended half-life, improved epithelium permeability and bioavailability, enhanced tissue targeting, and minimized side effects. The present review summarizes recent developments in nanodelivery of natural antioxidants and its application to combat pathological conditions associated with oxidative stress.