Nanoparticle-mediated growth factor delivery systems: A new way to treat Alzheimer's disease

New insights into targeted therapy of glioblastoma using smart nanoparticles

In recent times, the intersection of nanotechnology and biomedical research has given rise to nanobiomedicine, a captivating realm that holds immense promise for revolutionizing diagnostic and therapeutic approaches in the field of cancer. This innovative fusion of biology, medicine, and nanotechnology aims to create diagnostic and therapeutic agents with enhanced safety and efficacy, particularly in the realm of theranostics for various malignancies. Diverse inorganic, organic, and hybrid organic-inorganic nanoparticles, each possessing unique properties, have been introduced into this domain. This review seeks to highlight the latest strides in targeted glioblastoma therapy by focusing on the application of inorganic smart nanoparticles. Beyond exploring the general role of nanotechnology in medical applications, this review delves into groundbreaking strategies for glioblastoma treatment, showcasing the potential of smart nanoparticles through in vitro studies, in vivo investigations, and ongoing clinical trials.

Navigating the Nose-to-Brain Route: A Systematic Review on Lipid-Based Nanocarriers for Central Nervous System Disorders

Background: The blood–brain barrier (BBB) regulates brain substance entry, posing challenges for treating brain diseases. Traditional methods face limitations, leading to the exploration of non-invasive intranasal drug delivery. This approach exploits the direct nose-to-brain connection, overcoming BBB restrictions. Intranasal delivery enhances drug bioavailability, reduces dosage, and minimizes systemic side effects. Notably, lipid nanoparticles, such as solid lipid nanoparticles and nanostructured lipid carriers, offer advantages like improved stability and controlled release. Their nanoscale size facilitates efficient drug loading, enhancing solubility and bioavailability. Tailored lipid compositions enable optimal drug release, which is crucial for chronic brain diseases. This review assesses lipid nanoparticles in treating neuro-oncological and neurodegenerative conditions, providing insights for effective nose-to-brain drug delivery. Methods: A systematic search was conducted across major medical databases (PubMed, Ovid MEDLINE, and Scopus) up to 6 January 2024. The search strategy utilized relevant Medical Subject Heading (MeSH) terms and keywords related to “lipid nanoparticles”, “intranasal administration”, “neuro-oncological diseases”, and “neurodegenerative disorders”. This review consists of studies in vitro, in vivo, or ex vivo on the intranasal administration of lipid-based nanocarriers for the treatment of brain diseases. Results: Out of the initial 891 papers identified, 26 articles met the eligibility criteria after a rigorous analysis. The exclusion of 360 articles was due to reasons such as irrelevance, non-reporting selected outcomes, the article being a systematic literature review or meta-analysis, and lack of method/results details. This systematic literature review, focusing on nose-to-brain drug delivery via lipid-based nanocarriers for neuro-oncological, neurodegenerative, and other brain diseases, encompassed 60 studies. A temporal distribution analysis indicated a peak in research interest between 2018 and 2020 (28.3%), with a steady increase over time. Regarding drug categories, Alzheimer’s disease was prominent (26.7%), followed by antiblastic drugs (25.0%). Among the 65 drugs investigated, Rivastigmine, Doxorubicin, and Carmustine were the most studied (5.0%), showcasing a diverse approach to neurological disorders. Notably, solid lipid nanoparticles (SLNs) were predominant (65.0%), followed by nanostructured lipid carriers (NLCs) (28.3%), highlighting their efficacy in intranasal drug delivery. Various lipids were employed, with glyceryl monostearate being prominent (20.0%), indicating preferences in formulation. Performance assessment assays were balanced, with in vivo studies taking precedence (43.3%), emphasizing the translation of findings to complex biological systems for potential clinical applications. Conclusions: This systematic review reveals the transformative potential of intranasal lipid nanoparticles in treating brain diseases, overcoming the BBB. Positive outcomes highlight the effectiveness of SLNs and NLCs, which are promising new approaches for ailments from AD to stroke and gliomas. While celebrating progress, addressing challenges like nanoparticle toxicity is also crucial.

Nose-to-brain delivery of self-assembled curcumin-lactoferrin nanoparticles: Characterization, neuroprotective effect and in vivo pharmacokinetic study

Curcumin (CUR) is a natural polyphenol extract with significant antioxidant and anti-inflammatory effects, which indicates its great potential for neuroprotection. Lactoferrin (LF), a commonly used oral carrier and targeting ligand, has not been reported as a multifunctional nanocarrier for nose-to-brain delivery. This study aims to develop a nose-to-brain delivery system of curcumin-lactoferrin nanoparticles (CUR-LF NPs) and to further evaluate the neuroprotective effects in vitro and brain accumulation in vivo. Herein, CUR-LF NPs were prepared by the desolvation method with a particle size of 84.8 ± 6.5 nm and a zeta potential of +22.8 ± 4.3 mV. The permeability coefficient of CUR-LF NPs (4.36 ± 0.79 × 10−6 cm/s) was 50 times higher than that of CUR suspension (0.09 ± 0.04 × 10−6 cm/s) on MDCK monolayer, indicating that the nanoparticles could improve the absorption efficiency of CUR in the nasal cavity. Moreover, CUR-LF NPs showed excellent protection against Aβ25-35-induced nerve damage in PC12 cells. In vivo pharmacokinetic studies showed that the brain-targeting efficiency of CUR-LF NPs via IN administration was 248.1%, and the nose-to-brain direct transport percentage was 59.7%. Collectively, nose-to-brain delivery of CUR-LF NPs is capable of achieving superior brain enrichment and potential neuroprotective effects.

The Delivery and Activation of Growth Factors Using Nanomaterials for Bone Repair

Bone regeneration is a comprehensive process that involves different stages, and various growth factors (GFs) play crucial roles in the entire process. GFs are currently widely used in clinical settings to promote bone repair; however, the direct application of GFs is often limited by their fast degradation and short local residual time. Additionally, GFs are expensive, and their use may carry risks of ectopic osteogenesis and potential tumor formation. Nanomaterials have recently shown great promise in delivering GFs for bone regeneration, as they can protect fragile GFs and control their release. Moreover, functional nanomaterials can directly activate endogenous GFs, modulating the regeneration process. This review provides a summary of the latest advances in using nanomaterials to deliver exogenous GFs and activate endogenous GFs to promote bone regeneration. We also discuss the potential for synergistic applications of nanomaterials and GFs in bone regeneration, along with the challenges and future directions that need to be addressed.

Protein and Gene Delivery Systems for Neurodegenerative Disorders: Where Do We Stand Today?

It has been estimated that every year, millions of people are affected by neurodegenerative disorders, which complicate their lives and their caregivers' lives. To date, there has not been an approved pharmacological approach to provide the complete treatment of neurodegenerative disorders. The only available drugs may only relieve the symptoms or slow down the progression of the disease. The absence of any treatment is quite rational given that neurodegeneration occurs by the progressive loss of the function or structure of the nerve cells of the brain or the peripheral nervous system, which eventually leads to their death either by apoptosis or necrotic cell death. According to a recent study, even though adult brain cells are injured, they can revert to an embryonic state, which may help to restore their function. These interesting findings might open a new path for the development of more efficient therapeutic strategies to combat devastating neurodegenerative disorders. Gene and protein therapies have emerged as a rapidly growing field for various disorders, especially neurodegenerative diseases. Despite these promising therapies, the complete treatment of neurodegenerative disorders has not yet been achieved. Therefore, the aim of this review is to address the most up-to-date data for neurodegenerative diseases, but most importantly, to summarize the available delivery systems incorporating proteins, peptides, and genes that can potentially target such diseases and pass into the blood-brain barrier. The authors highlight the advancements, at present, on delivery based on the carrier, i.e., lipid, polymeric, and inorganic, as well as the recent studies on radiopharmaceutical theranostics.

Intranasal lipid nanocarriers: Uptake studies with fluorescently labeled formulations

Drug delivery by the intranasal route allows both systemic absorption and non-invasive brain targeting, due to the unique connection provided by the olfactory and trigeminal nerves between the brain and the external environment. Lipid nanocarriers can improve intranasal drug delivery by enhancing bioadhesion to nasal mucosa, and by protecting the encapsulated drug from biological degradation and transport efflux proteins. In this study two different biocompatible lipid nanocarriers were compared: nanoemulsions and solid lipid nanoparticles. The nasal uptake was investigated by labeling the nanocarriers lipid matrix with two fluorescent probes, 6-coumarin and rhodamine B, both lipophilic, yet characterized by different water solubility, in order to mimic the behavior of hypothetic drug compounds. Ex vivo permeation, in vivo pharmacokinetics and biodistribution studies were performed. 6-coumarin, water insoluble and therefore integral with the lipid matrix, was taken up to a limited extent, within a long timeframe, but with a proportionally more pronounced brain accumulation. In nanoemulsions soluble rhodamine B showed a relevant systemic uptake, with good bioavailability, likely due to the prompt release of the probe at the nasal mucosa.

Ultra-stable dextran conjugated prodrug micelles for oxidative stress and glycometabolic abnormality combination treatment of Alzheimer's disease

Sophisticated nanomedicines are continually being developed, but big obstacles remain before they finish the drug release mission. The first challenge is rupture possibility of structure when infinite dilution, competitive reaction of electrolytes and protein in blood circulation. In addition, low responsive drug release efficiency in the lesion site remains the major challenge for clinical application of nanomedicine combination treatment. In this study, we discussed the opportunities for Alzheimer's disease (AD) combination therapy based on the thermodynamically ultra-stable dextran conjugated prodrug micelles. Dextran-nateglinide conjugated prodrug micelles (NA) and dextran-vitamin E succinate conjugated prodrug micelles (VES) presented ultra-low critical micelle concentration of ~10^-5 mM and high physiological stability when challenged by NaCl, sodium dodecyl sulphate (SDS), dodecyl dimethyl benzyl ammonium chloride (DDBAC) and no rupture of structure happened. The NA/insulin polymer-drug conjugate micelles (NA/INS PDC) and VES/insulin polymer-drug conjugate micelles (VES/INS PDC) efficiently cleaved by reactive oxygen species (ROS), leading to over 80% release of the encapsulated and conjugated drugs. The combination of nateglinide and insulin, vitamin E succinate and insulin improved the glucose metabolism, reduced oxidative stress, improved the mitochondrial function and recovered the cognitive capacity of mice. This work demonstrated a paradigm for specific and high efficacy AD combination therapy.

Tuning three-dimensional nano-assembly in the mesoscale via bis(imino)pyridine molecular functionalization

We investigate the effect of bis(imino)pyridine (BIP) ligands in guiding self-assembly of semiconducting CdSe/ZnS quantum dots (QDs) into three-dimensional multi-layered shells with diameters spanning the entire mesoscopic range, from 200 nm to 2 μm. The assembly process is directed by guest-host interactions between the BIP ligands and a thermotropic liquid crystal (LC), with the latter's phase transition driving the process. Characterization of the shell structures, through scanning electron microscopy and dynamic light scattering, demonstrates that the average shell diameter depends on the BIP structure, and that changing one functional group in the chemical scaffold allows systematic tuning of shell sizes across the entire range. Differential scanning calorimetry confirms a relationship between shell sizes and the thermodynamic perturbation of the BIP molecules to the LC phase transition temperature, allowing analytical modeling of shell assembly energetics. This novel mechanism to controllably tune shell sizes over the entire mesoscale via one standard protocol is a significant development for research on in situ cargo/drug delivery platforms using nano-assembled structures.

Therapeutic potential of neurotrophic factors in Alzheimer's Disease

INTRODUCTION

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia among the elderly population. AD is accompanied with the dysregulation of specific neurotrophic factors (NTFs) and their receptors, which plays a critical role in neuronal degeneration. NTFs are small proteins with therapeutic potential for human neurodegenerative diseases. These growth factors are categorized into four families: neurotrophins, neurokines, the glial cell line-derived NTF family of ligands, and the newly discovered cerebral dopamine NTF/mesencephalic astrocyte-derived NTF family. NTFs are capable of preventing cell death in degenerative conditions and can increase the neuronal growth and function in these disorders. Nevertheless, the adverse side effects of NTFs delivery and poor diffusion of these factors in the brain restrict the efficacy of NTFs therapy in clinical situations.

MATERIALS AND METHODS

In this review, we focus on the current advances in the use of NTFs to treat AD and summarize previous experimental and clinical studies for supporting the protective and therapeutic effects of these factors.

CONCLUSION

Based on reports, NTFs are considered as new and promising candidates for treating AD and AD-associated cognitive impairment.

Human-Soybean Allergies: Elucidation of the Seed Proteome and Comprehensive Protein-Protein Interaction Prediction

The soybean crop, Glycine max (L.) Merr., is consumed by humans, Homo sapiens, worldwide. While the respective bodies of literature and -omics data for each of these organisms are extensive, comparatively few studies investigate the molecular biological processes occurring between the two. We are interested in elucidating the network of protein-protein interactions (PPIs) involved in human-soybean allergies. To this end, we leverage state-of-the-art sequence-based PPI predictors amenable to predicting the enormous comprehensive interactome between human and soybean. A network-based analytical approach is proposed, leveraging similar interaction profiles to identify candidate allergens and proteins involved in the allergy response. Interestingly, the predicted interactome can be explored from two complementary perspectives: which soybean proteins are predicted to interact with specific human proteins and which human proteins are predicted to interact with specific soybean proteins. A total of eight proteins (six specific to the human proteome and two to the soy proteome) have been identified and supported by the literature to be involved in human health, specifically related to immunological and neurological pathways. This study, beyond generating the most comprehensive human-soybean interactome to date, elucidated a soybean seed interactome and identified several proteins putatively consequential to human health.

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.

Towards precision nanomedicine for cerebrovascular diseases with emphasis on Cerebral Cavernous Malformation (CCM)

Introduction: Cerebrovascular diseases encompass various disorders of the brain vasculature, such as ischemic/hemorrhagic strokes, aneurysms, and vascular malformations, also affecting the central nervous system leading to a large variety of transient or permanent neurological disorders. They represent major causes of mortality and long-term disability worldwide, and some of them can be inherited, including Cerebral Cavernous Malformation (CCM), an autosomal dominant cerebrovascular disease linked to mutations in CCM1/KRIT1, CCM2, or CCM3/PDCD10 genes.Areas covered: Besides marked clinical and etiological heterogeneity, some commonalities are emerging among distinct cerebrovascular diseases, including key pathogenetic roles of oxidative stress and inflammation, which are increasingly recognized as major disease hallmarks and therapeutic targets. This review provides a comprehensive overview of the different clinical features and common pathogenetic determinants of cerebrovascular diseases, highlighting major challenges, including the pressing need for new diagnostic and therapeutic strategies, and focusing on emerging innovative features and promising benefits of nanomedicine strategies for early detection and targeted treatment of such diseases.Expert opinion: Specifically, we describe and discuss the multiple physico-chemical features and unique biological advantages of nanosystems, including nanodiagnostics, nanotherapeutics, and nanotheranostics, that may help improving diagnosis and treatment of cerebrovascular diseases and neurological comorbidities, with an emphasis on CCM disease.

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.

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.

Nerve growth factor in metabolic complications and Alzheimer's disease: Physiology and therapeutic potential

As the population ages, obesity and metabolic complications as well as neurological disorders are becoming more prevalent, with huge economic burdens on both societies and families. New therapeutics are urgently needed. Nerve growth factor (NGF), first discovered in 1950s, is a neurotrophic factor involved in regulating cell proliferation, growth, survival, and apoptosis in both central and peripheral nervous systems. NGF and its precursor, proNGF, bind to TrkA and p75 receptors and initiate protein phosphorylation cascades, resulting in changes of cellular functions, and are associated with obesity, diabetes and its complications, and Alzheimer's disease. In this article, we summarize changes in NGF levels in metabolic and neuronal disorders, the signal transduction initiated by NGF and proNGF, the physiological and pathophysiological relevance, and therapeutic potential in treating chronic metabolic diseases and cognitive decline.

Characterization and Mathematical Modeling of Alginate/Chitosan-Based Nanoparticles Releasing the Chemokine CXCL12 to Attract Glioblastoma Cells

Chitosan (Chit) currently used to prepare nanoparticles (NPs) for brain application can be complexed with negatively charged polymers such as alginate (Alg) to better entrap positively charged molecules such as CXCL12. A sustained CXCL12 gradient created by a delivery system can be used, as a therapeutic approach, to control the migration of cancerous cells infiltrated in peri-tumoral tissues similar to those of glioblastoma multiforme (GBM). For this purpose, we prepared Alg/Chit NPs entrapping CXCL12 and characterized them. We demonstrated that Alg/Chit NPs, with an average size of ~250 nm, entrapped CXCL12 with ~98% efficiency for initial mass loadings varying from 0.372 to 1.490 µg/mg NPs. The release kinetic profiles of CXCL12 were dependent on the initial mass loading, and the released chemokine from NPs after seven days reached 12.6%, 32.3%, and 59.9% of cumulative release for initial contents of 0.372, 0.744, and 1.490 µg CXCL12/mg NPs, respectively. Mathematical modeling of released kinetics showed a predominant diffusive process with strong interactions between Alg and CXCL12. The CXCL12-NPs were not toxic and did not promote F98 GBM cell proliferation, while the released CXCL12 kept its chemotaxis effect. Thus, we developed an efficient and tunable CXCL12 delivery system as a promising therapeutic strategy that aims to be injected into a hydrogel used to fill the cavity after surgical tumor resection. This system will be used to attract infiltrated GBM cells prior to their elimination by conventional treatment without affecting a large zone of healthy brain tissue.

Alzheimer's disease: review of current nanotechnological therapeutic strategies

Introduction: Alzheimer's Disease (AD) is a progressive neurodegenerative pathology characterized by the presence of neuritic plaques and neurofibrillary tangles. The most important markers in AD pathology include excessive accumulation of amyloid beta (Aβ₄₂) and phosphorylated tau (P-tau) proteins. One of the possible therapeutic strategies entails the elimination of such deposits by inhibiting Aβ aggregation. For years, one of the major problems in the treatment of AD has been the limited ability to deliver drugs to the brain for reasons related to poor solubility, low bioavailability, and the impact of the blood-brain barrier (BBB).Areas covered: In recent years, the authors have observed an increasing scientific interest in nanotechnological solutions as the factors potentially capable of facilitating the treatment of neurodegenerative diseases. The authors discuss recent reports regarding the use of nanotechnology in the therapy and treatment of AD.Expert opinion: The current advances in nanotechnology promise a chance to overcome the obstacles posed by said limitations. The size and diversity of nanoparticles in terms of both composition and shape create new possibilities for a variety of therapeutic applications, also in the context of the treatment and diagnostics of neurodegenerative diseases, for instance in combination with magnetic resonance imaging.

The Structure and Function of α, β and γ-Secretase as Therapeutic Target Enzymes in the Development of Alzheimer’s Disease: A Review

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Alzheimer's disease is a progressive neurodegenerative disorder that affects the central nervous system. There are several factors that cause AD, like, intracellular hyperphosphorylated Tau tangles, collection of extracellular Amyloid-β42 and generation of reactive oxygen species due to mitochondrial dysfunction. This review analyses the most active target of AD and both types of AD-like early-onset AD and late-onset AD. BACE1 is a β-secretase involved in the cleavage of amyloid precursor protein and the pathogenesis of Alzheimer's disease. The presenilin proteins play a critical role in the pathogenesis of Alzheimer malady by intervening the intramembranous cleavage of amyloid precursor protein and the generation of amyloid β. The two homologous proteins PS1 and PS2 speak to the reactant subunits of particular γ-secretase edifices that intercede an assortment of cellular processes. Natural products are common molecular platforms in drug development in AD. Many natural products are being tested in various animal model systems for their role as a potential therapeutic target in AD. Presently, there are a few theories clarifying the early mechanisms of AD pathogenesis. Recently, research advancements in the field of nanotechnology, which utilize macromolecular strategies to make drugs in nanoscale measurements, offer nanotechnology-based diagnostic tools and drug carriers which are highly sensitive for effective drug targeting in the treatment of Alzheimer’s disease.

Nanomaterials as Promising Alternative in the Infection Treatment

Both the prevalence of antibiotic resistance and the increased biofilm-associated infections are boosting the demand for new advanced and more effective treatment for such infections. In this sense, nanotechnology offers a ground-breaking platform for addressing this challenge. This review shows the current progress in the field of antimicrobial inorganic-based nanomaterials and their activity against bacteria and bacterial biofilm. Herein, nanomaterials preventing the bacteria adhesion and nanomaterials treating the infection once formed are presented through a classification based on their functionality. To fight infection, nanoparticles with inherent antibacterial activity and nanoparticles acting as nanovehicles are described, emphasizing the design of the carrier nanosystems with properties targeting the bacteria and the biofilm.

110th Anniversary: Nanoparticle mediated drug delivery for the treatment of Alzheimer's disease: Crossing the blood-brain barrier

Alzheimer's disease is an irreversible neurodegenerative disorder affecting approximately 6 million Americans, 90% of which are over the age of 65. The hallmarks of the disease are represented by amyloid plaques and neurofibrillary tangles. While the neuronal characteristics of Alzheimer's disease are well known, current treatments only provide temporary relief of the disease symptoms. Many of the approved therapeutic agents for the management of cognitive impairments associated with the disease are based on neurotransmitter or enzyme modulation. However, development of new treatment strategies is limited due to failures associated with poor drug solubility, low bioavailability, and the inability to overcome obstacles present along the drug delivery route. In addition, treatment technologies must overcome the challenges presented by the blood-brain barrier. This complex and highly regulated barrier surveys the biochemical, physicochemical, and structural features of nearby molecules at the periphery, only permitting passage of select molecules into the brain. To increase drug efficacy to the brain, many nanotechnology-based platforms have been developed. These methods for assisted drug delivery employ sophisticated design strategies and offer serveral advantages over traditional methods. For example, nanoparticles are generally low-cost technologies, which can be used for non-invasive administrations, and formulations are highly tunable to increase drug loading, targeting, and release efficacy. These nanoscale systems can facilitate passage of drugs through the blood-brain barrier, thus improving the bioavailability, pharmacokinetics, and pharmacodynamics of therapeutic agents. Examples of such nanocarriers which are discussed herein include polymeric nanoparticles, dendrimers, and lipid-based nanoparticles.

Nose-to-brain delivery of hyaluronate - FG loop peptide conjugate for non-invasive hypoxic-ischemic encephalopathy therapy

The intranasal drug administration has attracted great interest as a non-invasive route allowing targeted delivery of drugs directly to the brain. However, one of the main issues in nasal drug administration is mucociliary clearance. Hyaluronate (HA) has been widely used as a mucoadhesive excipient for ocular, rectal, and vaginal delivery. Here, FG loop peptide (FGL) was conjugated to HA for improving enzymatic stability and delivery efficiency from the nose to the brain. The successful conjugation of FGL to aldehyde modified HA was confirmed by gel permeation chromatography (GPC) and ¹H nuclear magnetic resonance (NMR). The outstanding enzymatic stability of HA-FGL conjugate was also corroborated by the GPC. The HA-FGL conjugate showed enhanced binding affinity onto nasal epithelial cells. In addition, in vivo nose-to-brain delivery of HA-FGL conjugate could be visualized by using an IVIS imaging system and fluorescence microscopy. Finally, in vivo therapeutic effect of HA-FGL conjugate was successfully confirmed by histological analysis, transferase-mediated uridine 5-triphosphate-biotin nick end-labeling (TUNEL) assay, immunofluorescent staining, transmission electron microscopy (TEM), and rotarod tests in hypoxic-ischemic encephalopathy model animals.

Recent Status of Nanomaterial Fabrication and Their Potential Applications in Neurological Disease Management

Nanomaterials (NMs) are receiving remarkable attention due to their unique properties and structure. They vary from atoms and molecules along with those of bulk materials. They can be engineered to act as drug delivery vehicles to cross blood-brain barriers (BBBs) and utilized with better efficacy and safety to deliver specific molecules into targeted cells as compared to conventional system for neurological disorders. Depending on their properties, various metal chelators, gold nanoparticles (NPs), micelles, quantum dots, polymeric NPs, liposomes, solid lipid NPs, microparticles, carbon nanotubes, and fullerenes have been utilized for various purposes including the improvement of drug delivery system, treatment response assessment, diagnosis at early stage, and management of neurological disorder by using neuro-engineering. BBB regulates micro- and macromolecule penetration/movement, thus protecting it from many kinds of illness. This phenomenon also prevents drug delivery for the neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis, amyotrophic lateral sclerosis, and primary brain tumors. For some neurological disorders (AD and PD), the environmental pollution was considered as a major cause, as observed that metal and/or metal oxide from different sources are inhaled and get deposited in the lungs/brain. Old age, obesity, diabetes, and cardiovascular disease are other factors for rapid deterioration of human health and onset of AD. In addition, gene mutations have also been examined to cause the early onset familial forms of AD. AD leads to cognitive impairment and plaque deposits in the brain leading to neuronal cell death. Based on these facts and considerations, this review elucidates the importance of frequently used metal chelators, NMs and/or NPs. The present review also discusses the current status and future challenges in terms of their application in drug delivery for neurological disease management.

Advances in Glioblastoma Multiforme Treatment: New Models for Nanoparticle Therapy

The most lethal form of brain cancer, glioblastoma multiforme, is characterized by rapid growth and invasion facilitated by cell migration and degradation of the extracellular matrix. Despite technological advances in surgery and radio-chemotherapy, glioblastoma remains largely resistant to treatment. New approaches to study glioblastoma and to design optimized therapies are greatly needed. One such approach harnesses computational modeling to support the design and delivery of glioblastoma treatment. In this paper, we critically summarize current glioblastoma therapy, with a focus on emerging nanomedicine and therapies that capitalize on cell-specific signaling in glioblastoma. We follow this summary by discussing computational modeling approaches focused on optimizing these emerging nanotherapeutics for brain cancer. We conclude by illustrating how mathematical analysis can be used to compare the delivery of a high potential anticancer molecule, delphinidin, in both free and nanoparticle loaded forms across the blood-brain barrier for glioblastoma.

Lipid nanoparticles for intranasal administration: application to nose-to-brain delivery

INTRODUCTION

The blood brain barrier is a functional barrier allowing the entry into the brain of only essential nutrients, excluding other molecules. Its structure, although essential to keep the harmful entities out, is also a major roadblock for pharmacological treatment of brain diseases. Several alternative invasive drug delivery approaches, such as transcranial drug delivery and disruption of blood brain barrier have been explored, with limited success and several challenges. Intranasal delivery is a non-invasive methodology, which bypasses the systemic circulation, and, through the intra- and extra- neuronal pathways, provides direct brain drug delivery. Colloidal drug delivery systems, particularly lipidic nanoparticles offer several unique advantages for this goal.

AREAS COVERED

This review focuses on key brain diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis, and provide a detailed overview of the current lipid nanoparticle based treatment options explored thus far. The review also delves into basic preparation, challenges and evaluation methods of lipid drug delivery systems.

EXPERT OPINION

Brain diseases present complex pathophysiology, in addition to the practically inaccessible brain tissues, hence according to the authors, a two-pronged approach utilizing new target discovery coupled with new drug delivery systems such as lipid carriers must be adopted.

Growth Factor Delivery Systems for Tissue Engineering and Regenerative Medicine

Growth factors (GFs) are often a key component in tissue engineering and regenerative medicine approaches. In order to fully exploit the therapeutic potential of GFs, GF delivery vehicles have to meet a number of key design criteria such as providing localized delivery and mimicking the dynamic native GF expression levels and patterns. The use of biomaterials as delivery systems is the most successful strategy for controlled delivery and has been translated into different commercially available systems. However, the risk of side effects remains an issue, which is mainly attributed to insufficient control over the release profile. This book chapter reviews the current strategies, chemistries, materials and delivery vehicles employed to overcome the current limitations associated with GF therapies.

Characterization of alginate/chitosan-based nanoparticles and mathematical modeling of their SpBMP-9 release inducing neuronal differentiation of human SH-SY5Y cells

The incidence of brain degenerative disease such as Alzheimer's disease (AD) will increase as the world population is ageing. While current AD treatments have only a transient effect, there are many evidences indicating that some growth factors, such as BMP-9, may be used to treat AD. However, growth factors cannot readily access the brain because of their size and the presence of the blood brain barrier. We have therefore developed a small peptide derived from BMP-9, SpBMP-9, which can promote the differentiation of cholinergic neurons and inactivate GSK3beta, a Tau kinase. Here, we investigated the potential of a nanoparticle-based delivery system of SpBMP-9, made of alginate and chitosan (Alg/Chit NPs), as a new therapeutic strategy against AD. The Alg/Chit NPs size distribution revealed NPs with an average diameter of ∼240nm. The encapsulation efficiency of SpBMP-9 was ∼70% of the initial peptide mass loading. Release kinetics of SpBMP-9 were performed in physiological conditions and modelled with a mechanistic framework that took into account the size distribution of Alg/Chit NPs. The release of SpBMP-9 revealed to be mostly diffusive, but there were interactions between the peptide and the alginate chains. The Alg/Chit NPs could also increase the viability of SH-SY5Y cells in comparison to the control. Finally, the SpBMP-9 released from Alg/Chit NPs promoted the SH-SY5Y differentiation into mature neurons as demonstrated by a higher neurite outgrowth and an increased expression of the neuronal markers NSE and VAchT. In conclusion, the nano-scale SpBMP-9 delivery system made of Alg/Chit may be a promising therapeutic strategy against AD.

Advances in structural design of lipid-based nanoparticle carriers for delivery of macromolecular drugs, phytochemicals and anti-tumor agents

The present work highlights recent achievements in development of nanostructured dispersions and biocolloids for drug delivery applications. We emphasize the key role of biological small-angle X-ray scattering (BioSAXS) investigations for the nanomedicine design. A focus is given on controlled encapsulation of small molecular weight phytochemical drugs in lipid-based nanocarriers as well as on encapsulation of macromolecular siRNA, plasmid DNA, peptide and protein pharmaceuticals in nanostructured nanoparticles that may provide efficient intracellular delivery and triggered drug release. Selected examples of utilisation of the BioSAXS method for characterization of various types of liquid crystalline nanoorganizations (liposome, spongosome, cubosome, hexosome, and nanostructured lipid carriers) are discussed in view of the successful encapsulation and protection of phytochemicals and therapeutic biomolecules in the hydrophobic or the hydrophilic compartments of the nanocarriers. We conclude that the structural design of the nanoparticulate carriers is of crucial importance for the therapeutic outcome and the triggered drug release from biocolloids.

Self-assembly of anionic, ligand-coated nanoparticles in lipid membranes

Ligand-functionalized nanoparticles (NPs) are a promising platform for imaging and drug delivery applications. A number of recent molecular simulation and theoretical studies explored how these NPs interact with model lipid membranes. However, interactions between ligand-coated NPs leading to possible cooperative effects and association have not been investigated. In this coarse-grained molecular dynamics study, we focus on a specific case of several anionic, ligand-coated NPs embedded in a lipid membrane. Several new effects are observed. Specifically, in the presence of cholesterol in the membrane, NPs tend to form linear clusters, or chains. Analysis of the driving forces for this association reveals an important role of the recently discovered orderphobic effect, although we acknowledge that a combination of factors must be at play. At the same time, we argue that the specific linear shape of the clusters is a result of a subtle balance between the forces that stabilize a NP in the membrane and the forces that drive the NP-NP association processes. These effects, observed for the first time in the NP-membrane systems, have also direct correspondence to similar effects in protein-membrane systems and these links between the two realms should be explored further.

Development and Characterization of VEGF165-Chitosan Nanoparticles for the Treatment of Radiation-Induced Skin Injury in Rats

Radiation-induced skin injury, which remains a serious concern in radiation therapy, is currently believed to be the result of vascular endothelial cell injury and apoptosis. Here, we established a model of acute radiation-induced skin injury and compared the effect of different vascular growth factors on skin healing by observing the changes of microcirculation and cell apoptosis. Vascular endothelial growth factor (VEGF) was more effective at inhibiting apoptosis and preventing injury progression than other factors. A new strategy for improving the bioavailability of vascular growth factors was developed by loading VEGF with chitosan nanoparticles. The VEGF-chitosan nanoparticles showed a protective effect on vascular endothelial cells, improved the local microcirculation, and delayed the development of radioactive skin damage.

Biomaterials for the Treatment of Alzheimer's Disease

Alzheimer’s disease (AD) as a progressive and fatal neurodegenerative disease represents a huge unmet need for treatment. The low efficacy of current treatment methods is not only due to low drug potency but also due to the presence of various obstacles in the delivery routes. One of the main barriers is the blood–brain barrier. The increasing prevalence of AD and the low efficacy of current therapies have increased the amount of research on unraveling of disease pathways and development of treatment strategies. One of the interesting areas for the latter subject is biomaterials and their applications. This interest originates from the fact that biomaterials are very useful for the delivery of therapeutic agents, such as drugs, proteins, and/or cells, in order to treat diseases and regenerate tissues. Recently, manufacturing of nano-sized delivery systems has increased the efficacy and delivery potential of biomaterials. In this article, we review the latest developments with regard to the use of biomaterials for the treatment of AD, including nanoparticles and liposomes for delivery of therapeutic compounds and scaffolds for cell delivery strategies.

Current applications of nanoparticles in infectious diseases

For decades infections have been treated easily with drugs. However, in the 21st century, they may become lethal again owing to the development of antimicrobial resistance. Pathogens can become resistant by means of different mechanisms, such as increasing the time they spend in the intracellular environment, where drugs are unable to reach therapeutic levels. Moreover, drugs are also subject to certain problems that decrease their efficacy. This requires the use of high doses, and frequent administrations must be implemented, causing adverse side effects or toxicity. The use of nanoparticle systems can help to overcome such problems and increase drug efficacy. Accordingly, there is considerable current interest in their use as antimicrobial agents against different pathogens like bacteria, virus, fungi or parasites, multidrug-resistant strains and biofilms; as targeting vectors towards specific tissues; as vaccines and as theranostic systems. This review begins with an overview of the different types and characteristics of nanoparticles used to deliver drugs to the target, followed by a review of current research and clinical trials addressing the use of nanoparticles within the field of infectious diseases.

Nano-antioxidants: An emerging strategy for intervention against neurodegenerative conditions

Oxidative stress has for long been linked to the neuronal cell death in many neurodegenerative conditions. Conventional antioxidant therapies have been less effective in preventing neuronal damage caused by oxidative stress due to their inability to cross the blood brain barrier. Nanoparticle antioxidants constitute a new wave of antioxidant therapies for prevention and treatment of diseases involving oxidative stress. It is believed that nanoparticle antioxidants have strong and persistent interactions with biomolecules and would be more effective against free radical induced damage. Nanoantioxidants include inorganic nanoparticles possessing intrinsic antioxidant properties, nanoparticles functionalized with antioxidants or antioxidant enzymes to function as an antioxidant delivery system. Nanoparticles containing antioxidants have shown promise as high-performance therapeutic nanomedicine in attenuating oxidative stress with potential applications in treating and preventing neurodegenerative conditions. However, to realize the full potential of nanoantioxidants, negative aspects associated with the use of nanoparticles need to be overcome to validate their long term applications.