Current approaches to enhance CNS delivery of drugs across the brain barriers

Advancing Alzheimer's Therapy: Computational strategies and treatment innovations

Alzheimer's disease (AD) is a multifaceted neurodegenerative condition distinguished by the occurrence of memory impairment, cognitive deterioration, and neuronal impairment. Despite extensive research efforts, conventional treatment strategies primarily focus on symptom management, highlighting the need for innovative therapeutic approaches. This review explores the challenges of AD treatment and the integration of computational methodologies to advance therapeutic interventions. A comprehensive analysis of recent literature was conducted to elucidate the broad scope of Alzheimer's etiology and the limitations of conventional drug discovery approaches. Our findings underscore the critical role of computational models in elucidating disease mechanisms, identifying therapeutic targets, and expediting drug discovery. Through computational simulations, researchers can predict drug efficacy, optimize lead compounds, and facilitate personalized medicine approaches. Moreover, machine learning algorithms enhance early diagnosis and enable precision medicine strategies by analyzing multi-modal datasets. Case studies highlight the application of computational techniques in AD therapeutics, including the suppression of crucial proteins implicated in disease progression and the repurposing of existing drugs for AD management. Computational models elucidate the interplay between oxidative stress and neurodegeneration, offering insights into potential therapeutic interventions. Collaborative efforts between computational biologists, pharmacologists, and clinicians are essential to translate computational insights into clinically actionable interventions, ultimately improving patient outcomes and addressing the unmet medical needs of individuals affected by AD. Overall, integrating computational methodologies represents a promising paradigm shift in AD therapeutics, offering innovative solutions to overcome existing challenges and transform the landscape of AD treatment.

Functionalized Nanoparticles: A Promising Approach for Effective Management of Alzheimer's Disease

The severe neurodegenerative disease known as Alzheimer's disease (AD) is typified by a progressive loss of memory and cognitive function. The prevalence of AD is rising due to an aging global population, calling for novel treatment strategies. A potential treatment option for AD that shows promise is the use of functionalized nanoparticles (NPs). Recent developments in the synthesis, design, and use of functionalized NPs in AD therapy are examined in this review. An outline of the pathophysiological mechanisms underlying AD is given in the first section, focusing on the roles played by tau protein aggregates and amyloid-beta plaques in the development of the illness. We then explore the many approaches used to functionalize NPs, such as surface alterations and bioconjugation methods, which enable accurate drug administration, targeted delivery, and enhanced biocompatibility. The review also emphasizes the therapeutic potential of functionalized NPs, highlighting their capacity to improve neuroprotection, lower amyloid-beta aggregation, and improve blood-brain barrier penetration. The potential of NPs as a tool for disease modification and symptom relief is highlighted by recent pre-clinical and clinical research. Concerns about toxicity and safety are also covered, underscoring the significance of thorough testing and the field's future directions. Functionalized NPs have great promise as a multimodal strategy to treat AD, offering patients hope for better quality of life, early diagnosis, and efficient disease treatment. This study highlights the growing role of nanotechnology in the search for novel and potent therapies for AD.

Polymer-based nanocarriers to transport therapeutic biomacromolecules across the blood-brain barrier

Therapeutic biomacromolecules such as genetic material, antibodies, growth factors and enzymes represent a novel therapeutic alternative for neurological diseases and disorders. In comparison to traditional therapeutics, which are mainly based on small molecular weight drugs that address the symptoms of these disorders, therapeutic biomacromolecules can reduce undesired side effects and target specific pathological pathways, thus paving the way towards personalized medicine. However, these biomacromolecules undergo degradation/denaturation processes in the physiological environment and show poor capacity to cross the blood-brain barrier (BBB). Consequently, they rarely reach the central nervous system (CNS) in their active form. Herein, we critically overview several polymeric nanocarriers that can protect and deliver therapeutic biomacromolecules across the BBB. Polymeric nanocarriers are first categorized based on their architecture (biodegradable solid nanoparticles, nanogels, dendrimers, self-assembled nanoparticles) that ultimately determines their physico-chemical properties and function. The available polymeric formulations are then thoroughly analyzed, placing particular attention on those strategies that ensure the stability of the biomacromolecules during their encapsulation process and promote their passage across the BBB by controlling their physical (e.g., mechanical properties, size, surface charge) and chemical (e.g., surface functional groups, targeting motifs) properties. Accordingly, this review gives a unique perspective on polymeric nanocarriers for the delivery of therapeutic biomacromolecules across the BBB, representing a concise, complete and easy-to-follow guide, which will be of high interest for chemists, material scientists, pharmacologists, and biologists. Besides, it also provides a critical perspective about the limited clinical translation of these systems. STATEMENT OF SIGNIFICANCE: The increasing incidence of central nervous system disorders is a major health concern. The use of therapeutic biomacromolecules has been placed in the spotlight of many investigations. However, reaching therapeutic concentration levels of biomacromolecules in the central nervous system is restricted by the blood-brain barrier and, thus, this represents the main clinical challenge when developing efficient therapies. Herein, we provide a critical discussion about the use of polymeric nanocarriers to deliver therapeutic biomacromolecules into the central nervous system, highlighting potential future directions to overcome the current challenges.

Nanoscale drug formulations for the treatment of Alzheimer's disease progression

Alzheimer's disease (AD) is a devastating neurodegenerative disorder with no effective disease-modifying treatments. The blood-brain barrier hinders drug delivery to the brain, limiting therapeutic efficacy. Nanoparticle-based systems have emerged as promising tools to overcome these challenges. This review highlights recent advances in nanoparticle technologies for AD treatment, including liposomes, polymeric, inorganic, and biomimetic nanoparticles. These nanoparticles improve drug delivery across the blood-brain barrier, improve stability and bioavailability, and enable targeted delivery to affected brain regions. Functionalization strategies further enhance their therapeutic potential. Multifunctional nanoparticles combining therapeutic and diagnostic properties offer theranostic approaches. While progress has been made, challenges related to safety, targeting precision, and clinical translation remain. Future perspectives emphasize the need for collaborative efforts to optimize nanoparticle design, conduct rigorous studies, and accelerate the development of effective nanotherapeutics. With continued innovation, nanoparticle-based delivery systems hold great promise for revolutionizing AD treatment.

Emerging nanoplatforms towards microenvironment-responsive glioma therapy

Gliomas are aggressive intracranial tumors of the central nervous system with a poor prognosis, high risk of recurrence, and low survival rates. Radiation, surgery, and chemotherapy are traditional cancer therapies. It is very challenging to accurately image and differentiate the malignancy grade of gliomas due to their heterogeneous and infiltrating nature and the obstruction of the blood-brain barrier. Imaging plays a crucial role in gliomas which significantly plays an important role in the accuracy of the diagnosis followed by any subsequent surgery or therapy. Other diagnostic methods (such as biopsies or surgery) are often very invasive. Preoperative imaging and intraoperative image-guided surgery perform the most significant safe resection. In recent years, the rapid growth of nanotechnology has opened up new avenues for glioma diagnosis and treatment. For better therapeutic efficacy, developing microenvironment-responsive nanoplatforms, including novel nanotherapeutic platforms of sonodynamic therapy, photodynamic therapy, and photothermal treatments, are employed for improved patient survival and better clinical control outcome. In this review recent advancement of multifunctional nanoplatforms leading toward treatment of glioma is discussed.

Polymeric Nanoparticles Revolutionizing Brain Cancer Therapy: A Comprehensive Review of Strategies and Advances

Brain cancer continues to be one of the most formidable malignancies to manage, mainly attributable to the presence of the blood-brain barrier (BBB) limiting the permeability of drugs and the diverse characteristics of brain tumors complicating treatment. The management of brain tumors has been hampered by many different factors, including the impermeability of the BBB, which restricts the delivery of chemotherapeutic agents to the tumor site, as well as intertumoral heterogeneity and the influence of brain tumor stem cells. In addition, small molecular weight drugs cannot specifically accumulate in malignant cells and have a limited circulation half-life. Nanoparticles (NPs) can be engineered to traverse the BBB and transport therapeutic medications directly into the brain, enhancing their efficacy compared with the conventional delivery of unbound drugs. Surface modifications of NPs can boost their efficiency by increasing their selectivity towards tumor receptors. This review covers treatment methods for malignant gliomas, associated risk factors, and improvements in brain drug administration, emphasizing the future potential of polymeric NPs and their mechanism for crossing the BBB. To surmount these obstacles, the newly formulated drug-delivery approach utilizing NPs, particularly those coated with cell membranes, has demonstrated potential in treating brain cancer. These NPs provide targeted tumor specificity, biocompatibility, extended circulation, enhanced BBB penetration, and immune evasion. This review focuses on coating strategies for PLGA NPs, particularly dual-targeting methods, to enhance BBB permeability and tumor-targeted delivery of drugs in brain cancer.

Advancements and challenges in brain cancer therapeutics

Treating brain tumors requires a nuanced understanding of the brain, a vital and delicate organ. Location, size, tumor type, and surrounding tissue health are crucial in developing treatment plans. This review comprehensively summarizes various treatment options that are available or could be potentially available for brain tumors, including physical therapies (radiotherapy, ablation therapy, photodynamic therapy, tumor-treating field therapy, and cold atmospheric plasma therapy) and non-physical therapies (surgical resection, chemotherapy, targeted therapy, and immunotherapy). Mechanisms of action, potential side effects, indications, and latest developments, as well as their limitations, are highlighted. Furthermore, the requirements for personalized, multi-modal treatment approaches in this rapidly evolving field are discussed, emphasizing the balance between efficacy and patient safety.

Non-Invasive Techniques of Nose to Brain Delivery Using Nanoparticulate Carriers: Hopes and Hurdles

Intranasal drug delivery route has emerged as a promising non-invasive method of administering drugs directly to the brain, bypassing the blood-brain barrier (BBB) and blood-cerebrospinal fluid barriers (BCSF). BBB and BCSF prevent many therapeutic molecules from entering the brain. Intranasal drug delivery can transport drugs from the nasal mucosa to the brain, to treat a variety of Central nervous system (CNS) diseases. Intranasal drug delivery provides advantages over invasive drug delivery techniques such as intrathecal or intraparenchymal which can cause infection. Many strategies, including nanocarriers liposomes, solid-lipid NPs, nano-emulsion, nanostructured lipid carriers, dendrimers, exosomes, metal NPs, nano micelles, and quantum dots, are effective in nose-to-brain drug transport. However, the biggest obstacles to the nose-to-brain delivery of drugs include mucociliary clearance, poor drug retention, enzymatic degradation, poor permeability, bioavailability, and naso-mucosal toxicity. The current review aims to compile current approaches for drug delivery to the CNS via the nose, focusing on nanotherapeutics and nasal devices. Along with a brief overview of the related pathways or mechanisms, it also covers the advantages of nasal drug delivery as a potential method of drug administration. It also offers several possibilities to improve drug penetration across the nasal barrier. This article overviews various in-vitro, ex-vivo, and in-vivo techniques to assess drug transport from the nasal epithelium into the brain.

Designing and optimizing AAV-mediated gene therapy for neurodegenerative diseases: from bench to bedside

Recombinant adeno-associated viruses (rAAVs) have emerged as an attractive tool for gene delivery, and demonstrated tremendous promise in gene therapy and gene editing-therapeutic modalities with potential "one-and-done" treatment benefits compared to conventional drugs. Given their tropisms for the central nervous system (CNS) across various species including humans, rAAVs have been extensively investigated in both pre-clinical and clinical studies targeting neurodegenerative disease. However, major challenges remain in the application of rAAVs for CNS gene therapy, such as suboptimal vector design, low CNS transduction efficiency and specificity, and therapy-induced immunotoxicity. Therefore, continuing efforts are being made to optimize the rAAV vectors from their "core" genetic payloads to their "coat" or capsid structure. In this review, we describe current approaches for rAAV vector design tailored for transgene expression in the CNS, summarize the development of CNS-targeting AAV serotypes, and highlight recent advancements in AAV capsid engineering, aimed at generating a new generation of rAAVs with improved CNS tropism. Additionally, we discuss various administration routes for delivering rAAVs to the CNS and provide an overview of AAV-mediated gene therapies currently under investigation in clinical trials for the treatment of neurodegenerative diseases.

Estimating the therapeutic potential of NSAIDs and linoleic acid-isomers supplementation against neuroinflammation

Nonsteroidal anti-inflammatory drugs (NSAIDs) regulate inflammation, which is associated with their role in preventing neurodegenerative diseases in epidemiological studies. It has sparked interest in their unconventional application for reducing neuroinflammation, opening up new avenues in biomedical research. However, given the pharmacological drawbacks of NSAIDs, the development of formulations with naturally antioxidant/anti-inflammatory dietary fatty acids has been demonstrated to be advantageous for the clinical translation of anti-inflammatory-based therapies. It includes improved blood-brain barrier (BBB) permeability and reduced toxicity. It permits us to speculate about the value of linoleic acid (LA)-isomers in preventing and treating neuroinflammatory diseases compared to NSAIDs. Our research delved into the impact of various factors, such as administration route, dosage, timing of intervention, and BBB permeability, on the efficacy of NSAIDs and LA-isomers in preclinical and clinical settings. We conducted a systematic comparison between NSAIDs and LA-isomers regarding their therapeutic effectiveness, BBB compatibility, and side effects. Additionally, we explored their underlying mechanisms in addressing neuroinflammation. Through our analysis, we've identified challenges and drawn conclusions that could propel advancements in treating neurodegenerative diseases and inform the development of future alternative therapeutic strategies.

Drug product Formulation and Fill/Finish Manufacturing Process Considerations for AAV-Based Genomic Medicines

Adeno-associated viruses (AAVs) have become the delivery medium of choice for a variety of genomic medicine applications i.e., gene therapy, gene editing/regulation, and ex-vivo cell therapy. AAVs are protein-DNA complexes which have unique stability characteristics that are susceptible to various stress exposure conditions commonly seen in the drug product (DP) life cycle. This review takes a comprehensive look at AAV DP formulation and process development considerations that could impact critical quality attributes (CQAs) during manufacturing, packaging, shipping, and clinical use. Additional aspects related to AAV development reviewed herein are: (1) Different AAV serotypes with unique protein sequences and charge characteristics potentially leading to discrete stability profiles; (2) Manufacturing process challenges and optimization efforts to improve yield, recovery and purity especially during early development activities; and (3) Defining and identifying CQAs with analytical methods which are constantly evolving and present unique characterization challenges for AAV-based products.

Validation of the Absorption-Enhancing Ability of Oligoarginines Grafted onto a Backbone of Hyaluronic Acid through Animal Studies from Rodents to Primates

The purpose of our research is to develop functional additives that enhance mucosal absorption of biologics, such as peptide/protein and antibody drugs, to provide their non-to-poor invasive dosage forms self-managed by patients. Our previous in vivo and in vitro studies demonstrated that the intranasal absorption of biologics in mice was significantly improved when coadministered with oligoarginines anchored chemically to hyaluronic acid via a glycine spacer, presumably through syndecan-4-mediated macropinocytosis under activation by oligoarginines. The present mouse experiments first revealed that diglycine-L-tetraarginine-linked hyaluronic acid significantly enhanced the intranasal absorption of sulpiride, which is a poor-absorptive organic compound with a low molecular weight. However, similar enhancement was not observed for levofloxacin, which has a similarly low molecular weight but is a well-absorptive organic compound, probably because its absorption was mostly dominated by passive diffusion. The subsequent monkey experiments revealed that there was no species difference in the absorption-enhancing ability of diglycine-L-tetraarginine-linked hyaluronic acid for not only organic compounds but also biologics. This was presumably because the expression levels of endocytosis-associated membrane proteins on the nasal mucosa in monkeys were almost equivalent to those in mice, and poorly membrane-permeable/membrane-impermeable drugs were mainly absorbed via syndecan-4-mediated macropinocytosis, regardless of animal species. Drug concentrations in the brain assessed in mice and monkeys and those in the cerebral spinal fluids (CSFs) assessed in monkeys indicated that drugs would be delivered from the systemic circulation to the central nervous system by crossing the blood-brain and the blood-CSF barriers under coadministration with the hyaluronic acid derivative. In line with our original hypothesis, this new set of data supported that our oligoarginine-linked hyaluronic acid would locally perform on the mucosal surface and enhance the membrane permeation of drugs under its colocalization.

Unraveling the therapeutic potential of quercetin and quercetin-3-O-glucuronide in Alzheimer's disease through network pharmacology, molecular docking, and dynamic simulations

Quercetin is a flavonoid with notable pharmacological effects and promising therapeutic potential. Quercetin plays a significant role in neuroinflammation, which helps reduce Alzheimer's disease (AD) severity. Quercetin (Q) and quercetin 3-O-glucuronide (Q3OG) are some of the most potent antioxidants available from natural sources. However, the natural form of quercetin converted into Q3OG when reacted with intestinal microbes. The study aims to ensure the therapeutic potential of Q and Q3OG. In this study, potential molecular targets of Q and Q3OG were first identified using the Swiss Target Prediction platform and pathogenic targets of AD were identified using the DisGeNET database. Followed by compound and disease target overlapping, 77 targets were placed in that AKT1, EGFR, MMP9, TNF, PTGS2, MMP2, IGF1R, MCL1, MET and PARP1 was the top-ranked target, which was estimated by CytoHubba plug-in. The Molecular docking was performed for Q and Q3OG towards the PDB:1UNQ target. The binding score of Q and Q3OG was - 6.2 kcal/mol and - 6.58 kcal/mol respectively. Molecular dynamics simulation was conducted for Q and Q3OG towards the PDB:1UNQ target at 200 ns. This study's results help identify the multiple target sites for the bioactive compounds. Thus, synthesizing new chemical entity-based quercetin on structural modification may aid in eradicating AD complications.

Nasal application of kisspeptin-54 mitigates motor deficits by reducing nigrostriatal dopamine loss in hemiparkinsonian rats

Parkinson's Disease is a progressive neurodegenerative disorder characterized by motor symptoms resulting from the loss of nigrostriatal dopaminergic neurons. Kisspeptins (KPs) are a family of neuropeptides that are encoded by the Kiss-1 gene, which exert their physiological effects through interaction with the GPR54 receptor. In the current investigation, we investigated the prospective protective effects of central KP-54 treatments on nigrostriatal dopaminergic neurons and consequent motor performance correlates in 6-hydroxydopamine (6-OHDA)-lesioned rats. Male adult Sprague Dawley rats underwent stereotaxic injection of 6-OHDA into the right medial forebrain bundle to induce hemiparkinsonism. Following surgery, rats received chronic central treatments of nasal or intracerebroventricular KP-54 (logarithmically increasing doses) for seven consecutive days. Motor performance was evaluated seven days post-surgery utilizing the open field test and catalepsy test. The levels of dopamine in the striatum were determined with mass spectrometry. Immunohistochemical analysis was conducted to assess the immunoreactivities of tyrosine hydroxylase (TH) and the GPR54 in the substantia nigra. The dose-response curve revealed a median effective dose value of ≈3 nmol/kg for both central injections. Due to its non-invasive and effective nature, nasal administration was utilized in the second phase of our study. Chronic administration of KP-54 (3nmol/kg, nasally) significantly protected 6-OHDA-induced motor deficits. Nasal KP-54 attenuated the loss of nigrostriatal dopaminergic neurons induced by 6-OHDA. Additionally, significant correlations were observed between motor performance and nigrostriatal dopamine levels. Immunohistochemical analysis demonstrated the localization of the GPR54 within TH-positive nigral cells. These findings suggest the potential efficacy of central KP-54 on motor impairments in hemiparkinsonism.

Exosome: From biology to drug delivery

In recent years, different advancements have been observed in nanosized drug delivery systems. Factors such as stability, safety and targeting efficiency cause hindrances in the clinical translation of these synthetic nanocarriers. Therefore, researchers employed endogenous nanocarriers like exosomes as drug delivery vehicles that have an inherent ability to target more efficiently after appropriate functionalization and show higher biocompatibility and less immunogenicity and facilitate penetration through the biological barriers more quickly than the other available carriers. Exosomes are biologically derived lipid bilayer-enclosed nanosized extracellular vesicles (size ranges from 30 to 150 nm) secreted from both prokaryotic and eukaryotic cells and appears significantly in the extracellular space. These EVs (extracellular vesicles) can exist in different sources, including mammals, plants and microorganisms. Different advanced techniques have been introduced for the isolation of exosomes to overcome the existing barriers present with conventional methods. Extensive research on the application of exosomes in therapeutic delivery for treating various diseases related to central nervous system, bone, cancer, skin, etc. has been employed. Several studies are on different stages of clinical trials, and many exosomes patents have been registered.

In-vitro and in-vivo assessment of nirmatrelvir penetration into CSF, central nervous system cells, tissues, and peripheral blood mononuclear cells

Three years after SARS-CoV-2 emerged as a global infectious threat, the virus has become endemic. The neurological complications such as depression, anxiety, and other CNS complications after COVID-19 disease are increasing. The brain, and CSF have been shown as viral reservoirs for SARS-CoV-2, yielding a potential hypothesis for CNS effects. Thus, we investigated the CNS pharmacology of orally dosed nirmatrelvir/ritonavir (NMR/RTV). Using both an in vitro and an in vivo rodent model, we investigated CNS penetration and potential pharmacodynamic activity of NMR. Through pharmacokinetic modeling, we estimated the median CSF penetration of NMR to be low at 18.11% of plasma with very low accumulation in rodent brain tissue. Based on the multiples of the 90% maximal effective concentration (EC90) for SARS-CoV-2, NMR concentrations in the CSF and brain do not achieve an exposure level similar to that of plasma. A median of only 16% of all the predicted CSF concentrations in rats were > 3xEC90 (unadjusted for protein binding). This may have implications for viral persistence and neurologic post-acute sequelae of COVID-19 if increased NMR penetration in the CNS leads to decreased CNS viral loads and decreased CNS inflammation.

A review of natural products and small-molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time-consuming nature of studies to find new anticancer agents makes it necessary to have well-designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi-synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal-oriented studies for drug development against CNS malignancies.

Formulation and characterization of polymeric nanoparticle of Rivastigmine for effective management of Alzheimer's disease

Memory loss or dementia is a progressive disorder, and one of its common forms is Alzheimer's disease (AD), effecting mostly middle aged and older adults. In the present study, we developed Rivastigmine (RIV) nanoparticles using poly(lactic-co-glycolic acid) (RIV-loaded PLGA NPs) and polyvinyl alcohol (PVA). The prepared RIV-PLGA nanoparticles was evaluated for the management of Alzheimer's disease (AD). The nanoparticles were prepared by the slightly modified nano-precipitation technique. The developed formulations were evaluated for particle size, zeta potential (ZP), polydispersibility index (PDI) and surface morphology and drug content. The experimental result revealed that prepared RIV-loaded PLGA NPs (F1) was optimized having particle size (61.2 ± 4.6 nm), PDI (0.292), ZP (-11.2 ± 1.2). SEM study confirms the prepared nanoparticles depicted non-aggregated as well smooth surface particles without any fracture. This formulation (F1) was further assessed for in vivo studies on animal model. A pharmacological screening on an animal model of Alzheimer's disease revealed that RIV-loaded PLGA NPs formulations treat CNS disorders like Alzheimer's effectively. In addition to that, an in-vivo brain cholinesterase estimation study found that, animals treated with optimized formulation significantly (p < 0.01) reduced brain cholinesterase activity when compared to scopolamine-treated animals. According to the above results, it can be concluded that RIV-loaded PLGA NPs are ideal carriers for delivering the drug at a specific target site in the brain, thus may treat Alzheimer's disease efficiently and improve patient compliance.

Neuroglia targeting nano-therapeutic approaches to rescue aging and neurodegenerating brain

Despite intense efforts at the bench, the development of successful brain-targeting therapeutics to relieve malicious neural diseases remains primitive. The brain, being a beautifully intricate organ, consists of heterogeneous arrays of neuronal and glial cells. Primarily acting as the support system for neuronal functioning and maturation, glial cells have been observed to be engaged more apparently in the progression and worsening of various neural pathologies. The diseased state is often related to metabolic alterations in glial cells, thereby modulating their physiological homeostasis in conjunction with neuronal dysfunction. A plethora of data indicates the effect of oxidative stress, protein aggregation, and DNA damage in neuroglia impairments. Still, a deeper insight is needed to gain a conflict-free understanding in this arena. As a consequence, glial cells hold the potential to be identified as promising targets for novel therapeutic approaches aimed at brain protection. In this review, we describe the recent strides taken in the direction of understanding the impact of oxidative stress, protein aggregation, and DNA damage on neuroglia impairment and neuroglia-directed nanotherapeutic approaches to mitigate the burden of various neural disorders.

Flexible neural probes: a review of the current advantages, drawbacks, and future demands

Brain diseases affect millions of people and have a huge social and economic impact. The use of neural probes for studies in animals has been the main approach to increasing knowledge about neural network functioning. Ultimately, neuroscientists are trying to develop new and more effective therapeutic approaches to treating neurological disorders. The implementation of neural probes with multifunctionalities (electrical, optical, and fluidic interactions) has been increasing in the last few years, leading to the creation of devices with high temporal and spatial resolution. Increasing the applicability of, and elements integrated into, neural probes has also led to the necessity to create flexible interfaces, reducing neural tissue damage during probe implantation and increasing the quality of neural acquisition data. In this paper, we review the fabrication, characterization, and validation of several types of flexible neural probes, exploring the main advantages and drawbacks of these devices. Finally, future developments and applications are covered. Overall, this review aims to present the currently available flexible devices and future appropriate avenues for development as possible guidance for future engineered devices.

Natural products and derivatives as Japanese encephalitis virus antivirals

Japanese encephalitis virus (JEV) causes acute Japanese encephalitis (JE) in humans and reproductive disorders in pigs. There are ~68 000 cases of JE worldwide each year, with ~13 600-20 400 deaths. JE infections have a fatality rate of one-third, and half of the survivors experience permanent neurological sequelae. The disease is prevalent throughout the Asia-Pacific region and has the potential to spread globally. JEV poses a serious threat to human life and health, and vaccination is currently the only strategy for long-term sustainable protection against JEV infection. However, licensed JEV vaccines are not effective against all strains of JEV. To date, there are no drugs approved for clinical use, and the development of anti-JEV drugs is urgently needed. Natural products are characterized by a wide range of sources, unique structures, and low prices, and this paper provides an overview of the research and development of anti-JEV bioactive natural products.

Biopolymers as promising vehicles for drug delivery to the brain

The brain is a privileged organ, tightly guarded by a network of endothelial cells, pericytes, and glial cells called the blood brain barrier. This barrier facilitates tight regulation of the transport of molecules, ions, and cells from the blood to the brain. While this feature ensures protection to the brain, it also presents a challenge for drug delivery for brain diseases. It is, therefore, crucial to identify molecules and/or vehicles that carry drugs, cross the blood brain barrier, and reach targets within the central nervous system. Biopolymers are large polymeric molecules obtained from biological sources. In comparison with synthetic polymers, biopolymers are structurally more complex and their 3D architecture makes them biologically active. Researchers are therefore investigating biopolymers as safe and efficient carriers of brain-targeted therapeutic agents. In this article, we bring together various approaches toward achieving this objective with a note on the prospects for biopolymer-based neurotherapeutic/neurorestorative/neuroprotective interventions. Finally, as a representative paradigm, we discuss the potential use of nanocarrier biopolymers in targeting protein aggregation diseases.

A multicellular brain spheroid model for studying the mechanisms and bioeffects of ultrasound-enhanced drug penetration beyond the blood‒brain barrier

The blood‒brain barrier (BBB) acts as a hindrance to drug therapy reaching the brain. With an increasing incidence of neurovascular diseases and brain cancer metastases, there is a need for an ideal in vitro model to develop novel methodologies for enhancing drug delivery to the brain. Here, we established a multicellular human brain spheroid model that mimics the BBB both architecturally and functionally. Within the spheroids, endothelial cells and pericytes localized to the periphery, while neurons, astrocytes, and microglia were distributed throughout. Ultrasound-targeted microbubble cavitation (UTMC) is a novel noninvasive technology for enhancing endothelial drug permeability. We utilized our three-dimensional (3D) model to study the feasibility and mechanisms regulating UTMC-induced hyperpermeability. UTMC caused a significant increase in the penetration of 10 kDa Texas red dextran (TRD) into the spheroids, 100 µm beyond the BBB, without compromising cell viability. This hyperpermeability was dependent on UTMC-induced calcium (Ca2+) influx and endothelial nitric oxide synthase (eNOS) activation. Our 3D brain spheroid model, with its intact and functional BBB, offers a valuable platform for studying the bioeffects of UTMC, including effects occurring spatially distant from the endothelial barrier.

Novel Targets and Drug Delivery System in the Treatment of Postoperative Pain: Recent Studies and Clinical Advancement

Pain is generated by a small number of peripheral targets. These can be made more sensitive by inflammatory mediators. The number of opioids prescribed to the patients can be reduced dramatically with better pain management. Any therapy that safely and reliably provides extended analgesia and is flexible enough to facilitate a diverse array of release profiles would be useful for improving patient comfort, quality of care, and compliance after surgical procedures. Comparisons are made between new and traditional methods, and the current state of development has been discussed; taking into account the availability of molecular and cellular level data, preclinical and clinical data, and early post-market data. There are a number of benefits associated with the use of nanotechnology in the delivery of analgesics to specific areas of the body. Nanoparticles are able to transport drugs to inaccessible bodily areas because of their small molecular size. This review focuses on targets that act specifically or primarily on sensory neurons, as well as inflammatory mediators that have been shown to have an analgesic effect as a side effect of their anti- inflammatory properties. New, regulated post-operative pain management devices that use existing polymeric systems were presented in this article, along with the areas for potential development. Analgesic treatments, both pharmacological and non-pharmacological, have also been discussed.

Microneedles: A Versatile Drug Delivery Carrier for Phytobioactive Compounds as a Therapeutic Modulator for Targeting Mitochondrial Dysfunction in the Management of Neurodegenerative Diseases

Neurodegenerative disease (ND) is the fourth leading cause of death worldwide, with limited symptomatic therapies. Mitochondrial dysfunction is a major risk factor in the progression of ND, and it-increases the generation of reactive oxygen species (ROS). Overexposure to these ROS induces apoptotic changes leading to neuronal cell death. Many studies have shown the prominent effect of phytobioactive compounds in managing mitochondrial dysfunctions associated with ND, mainly due to their antioxidant properties. The drug delivery to the brain is limited due to the presence of the blood-brain barrier (BBB), but effective drug concentration needs to reach the brain for the therapeutic action. Therefore, developing safe and effective strategies to enhance drug entry in the brain is required to establish ND's treatment. The microneedle-based drug delivery system is one of the effective non-invasive techniques for drug delivery through the transdermal route. Microneedles are micronsized drug delivery needles that are self-administrable. It can penetrate through the stratum corneum skin layer without hitting pain receptors, allowing the phytobioactive compounds to be released directly into systemic circulation in a controlled manner. With all of the principles mentioned above, this review discusses microneedles as a versatile drug delivery carrier for the phytoactive compounds as a therapeutic potentiating agent for targeting mitochondrial dysfunction for the management of ND.

Application of Nanocomposites and Nanoparticles in Treating Neurodegenerative Disorders

Neurodegenerative diseases represent a formidable global health challenge, affecting millions and imposing substantial burdens on healthcare systems worldwide. Conditions, like Alzheimer's, Parkinson's, and Huntington's diseases, among others, share common characteristics, such as neuronal loss, misfolded protein aggregation, and nervous system dysfunction. One of the major obstacles in treating these diseases is the presence of the blood-brain barrier, limiting the delivery of therapeutic agents to the central nervous system. Nanotechnology offers promising solutions to overcome these challenges. In Alzheimer's disease, NPs loaded with various compounds have shown remarkable promise in preventing amyloid-beta (Aβ) aggregation and reducing neurotoxicity. Parkinson's disease benefits from improved dopamine delivery and neuroprotection. Huntington's disease poses its own set of challenges, but nanotechnology continues to offer innovative solutions. The promising developments in nanoparticle-based interventions for neurodegenerative diseases, like amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS), have offered new avenues for effective treatment. Nanotechnology represents a promising frontier in biomedical research, offering tailored solutions to the complex challenges posed by neurodegenerative diseases. While much progress has been made, ongoing research is essential to optimize nanomaterial designs, improve targeting, and ensure biocompatibility and safety. Nanomaterials possess unique properties that make them excellent candidates for targeted drug delivery and neuroprotection. They can effectively bypass the blood-brain barrier, opening doors to precise drug delivery strategies. This review explores the extensive research on nanoparticles (NPs) and nanocomposites in diagnosing and treating neurodegenerative disorders. These nanomaterials exhibit exceptional abilities to target neurodegenerative processes and halt disease progression.

Apolipoprotein E3 functionalized lipid-drug conjugated nanoparticles of Levetiracetam for enhanced delivery to the brain: In-vitro cell line studies and in-vivo study

A significant portion of brain-tumor patients suffer from 'brain-tumor-related epilepsy (BTE)' which results in depression, anxiety and hampered quality of life. Conventional anti-epileptic drugs indicate negative interaction with other drugs augmenting the poor outcome of overall therapy. Levetiracetam (LVM) has evidenced effectiveness for BTE but its hydrophilicity restricts the passage into blood-brain barrier. The majority of lipid nanoparticles fails to load hydrophilic drug sufficiently. Therefore, lipid-drug conjugates (LDC) were synthesized using stearic acid via amide bond formation confirmed by FTIR and NMR. The nanoparticles of synthesized LDC were prepared by solvent injection method followed by functionalization with Apolipoprotein E3 (ApoE3@LDC-NP). The nanoparticles were characterized by DSC, XRD, particle size (131.6 ± 1.24 nm), zeta potential (-15.6 ± 0.09 mV), and for storage stability. In-vitro release study indicated initial burst release of 20 ± 0.63 % followed by sustained release up to 30 h (66 ± 1.40 %) for ApoE3@LDC-NP. The cell-line study on HEK293 indicated no significant cytotoxic effect and greater cell uptake through U87MG cell line. The pharmacokinetic and bio-distribution study indicated 2.5-fold greater brain-targeting of ApoE3@LDC-NP as compared to LVM solution. It proved safe in the haemolysis study and exhibited the absence of tissue necrosis. Thus, ApoE3@LDC-NP might be a promising approach for effective brain-targeting of LVM for improved clinical response in BTE.

Novel Biomaterials Based Strategies for Neurodegeneration: Recent Advancements and Future Prospects

Neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, pose significant challenges for effective treatment due to the complex nature of the central nervous system and the limited delivery of therapeutic agents to the brain. Biomaterial-based drug delivery systems offer promising strategies to overcome these challenges and improve therapeutic outcomes. These systems utilize various biomaterials, such as nanoparticles, hydrogels, and implants, to deliver drugs, genes, or cells to the affected regions of the brain. They provide advantages such as targeted delivery, controlled release, and protection of therapeutic agents. This review examines the role of biomaterials in drug delivery for neurodegeneration, discussing different biomaterialbased approaches, including surface modification, encapsulation, and functionalization techniques. Furthermore, it explores the challenges, future perspectives, and potential impact of biomaterialbased drug delivery systems in the field of neurodegenerative diseases.

Nose-to-Brain (N2B) Delivery: An Alternative Route for the Delivery of Biologics in the Management and Treatment of Central Nervous System Disorders

In recent years, there have been a growing number of small and large molecules that could be used to treat diseases of the central nervous system (CNS). Nose-to-brain delivery can be a potential option for the direct transport of molecules from the nasal cavity to different brain areas. This review aims to provide a compilation of current approaches regarding drug delivery to the CNS via the nose, with a focus on biologics. The review also includes a discussion on the key benefits of nasal delivery as a promising alternative route for drug administration and the involved pathways or mechanisms. This article reviews how the application of various auxiliary agents, such as permeation enhancers, mucolytics, in situ gelling/mucoadhesive agents, enzyme inhibitors, and polymeric and lipid-based systems, can promote the delivery of large molecules in the CNS. The article also includes a discussion on the current state of intranasal formulation development and summarizes the biologics currently in clinical trials. It was noted that significant progress has been made in this field, and these are currently being applied to successfully transport large molecules to the CNS via the nose. However, a deep mechanistic understanding of this route, along with the intimate knowledge of various excipients and their interactions with the drug and nasal physiology, is still necessary to bring us one step closer to developing effective formulations for nasal-brain drug delivery.

Druggable genomic landscapes of high-grade gliomas

Background

Despite the putatively targetable genomic landscape of high-grade gliomas, the long-term survival benefit of genomically-tailored targeted therapies remains discouraging.

Methods

Using glioblastoma (GBM) as a representative example of high-grade gliomas, we evaluated the clonal architecture and distribution of hotspot mutations in 388 GBMs from the Cancer Genome Atlas (TCGA). Mutations were matched with 54 targeted therapies, followed by a comprehensive evaluation of drug biochemical properties in reference to the drug's clinical efficacy in high-grade gliomas. We then assessed clinical outcomes of a cohort of patients with high-grade gliomas with targetable mutations reviewed at the Johns Hopkins Molecular Tumor Board (JH MTB; n = 50).

Results

Among 1,156 sequence alterations evaluated, 28.6% represented hotspots. While the frequency of hotspot mutations in GBM was comparable to cancer types with actionable hotspot alterations, GBMs harbored a higher fraction of subclonal mutations that affected hotspots (7.0%), compared to breast cancer (4.9%), lung cancer (4.4%), and melanoma (1.4%). In investigating the biochemical features of targeted therapies paired with recurring alterations, we identified a trend toward higher lipid solubility and lower IC50 in GBM cell lines among drugs with clinical efficacy. The drugs' half-life, molecular weight, surface area and binding to efflux transporters were not associated with clinical efficacy. Among the JH MTB cohort of patients with IDH1 wild-type high-grade gliomas who received targeted therapies, trametinib monotherapy or in combination with dabrafenib conferred radiographic partial response in 75% of patients harboring BRAF or NF1 actionable mutations. Cabozantinib conferred radiographic partial response in two patients harboring a MET and a PDGFRA/KDR amplification. Patients with IDH1 wild-type gliomas that harbored actionable alterations who received genotype-matched targeted therapy had longer progression-free (PFS) and overall survival (OS; 7.37 and 14.72 respectively) than patients whose actionable alterations were not targeted (2.83 and 4.2 months respectively).

Conclusion

While multiple host, tumor and drug-related features may limit the delivery and efficacy of targeted therapies for patients with high-grade gliomas, genotype-matched targeted therapies confer favorable clinical outcomes. Further studies are needed to generate more data on the impact of biochemical features of targeted therapies on their clinical efficacy for high-grade gliomas.

Rapid and Widespread Distribution of Intranasal Small Extracellular Vesicles Derived from Mesenchymal Stem Cells throughout the Brain Potentially via the Perivascular Pathway

Intranasal administration is a promising strategy to enhance the delivery of the sEVsomes-based drug delivery system to the central nervous system (CNS). This study aimed to explore central distributive characteristics of mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) and underlying pathways. Here, we observed that intranasal MSC-sEVs were rapidly distributed to various brain regions, especially in the subcortex distant from the olfactory bulb, and were absorbed by multiple cells residing in these regions. We captured earlier transportation of intranasal MSC-sEVs into the perivascular space and found an increase in cerebrospinal fluid influx after intranasal administration, particularly in subcortical structures of anterior brain regions where intranasal sEVs were distributed more significantly. These results suggest that the perivascular pathway may underlie the rapid and widespread central delivery kinetics of intranasal MSC-sEVs and support the potential of the intranasal route to deliver MSC-sEVs to the brain for CNS therapy.

Nanomaterials as drug delivery agents for overcoming the blood-brain barrier: A comprehensive review

Background and Purpose

The blood-brain barrier (BBB), a critical interface of specialized endothelial cells, plays a pivotal role in regulating molecular and ion transport between the central nervous system (CNS) and systemic circulation.

Experimental Approach

This review aims to delve into the intricate architecture and functions of the BBB while addressing challenges associated with delivering therapeutics to the brain. Historical milestones and contemporary insights underscore the BBB's significance in protecting the CNS.

Key Results

Innovative approaches for enhanced drug transport include intranasal delivery exploiting olfactory and trigeminal pathways, as well as techniques like temporary BBB opening through chemicals, receptors, or focused ultrasound. These avenues hold the potential to reshape conventional drug delivery paradigms and address the limitations posed by the BBB's selectivity.

Conclusion

This review underscores the vital role of the BBB in maintaining CNS health and emphasizes the importance of effective drug delivery through this barrier. Nanoparticles emerge as promising candidates to overcome BBB limitations and potentially revolutionize the treatment of CNS disorders. As research progresses, the application of nanomaterials shows immense potential for advancing neurological therapeutics, albeit with careful consideration of safety aspects.

Utility of a Novel Micro-Spraying Device for Intranasal Administration of Drug Solutions to Mice

Intranasal administration has attracted attention as a means of delivering drugs because it bypasses the blood-brain barrier. However, conventional intranasal administration of drug solutions to mice using the micropipette method (MP method) is complicated and time-consuming because it requires small doses to be administered under inhalation anesthesia. This study evaluated the effectiveness of a novel intranasal administration method using Micro FPS™, a novel micro-spraying device (the MSD method). The MSD method allowed more reliable administration of the solution to the nasal mucosa than the MP method did. The transfer of inulin, a model water-soluble macromolecule compound, to the olfactory bulb and brain (cerebrum, cerebellum, brainstem, and striatum) was similar with the two methods. It also allowed the drug to be administered in a shorter time. These results suggest that the MSD method is simpler and more rapid than the MP method for intranasal administration of drugs to mice and achieves comparable delivery of inulin to the olfactory bulb and brain. Therefore, the Micro FPS™ device is a potentially useful tool for intranasal drug administration to rodents and could facilitate the development of intranasal formulations, contributing to drug development for central nervous system diseases.

Recent Advancements and Strategies for Overcoming the Blood-Brain Barrier Using Albumin-Based Drug Delivery Systems to Treat Brain Cancer, with a Focus on Glioblastoma

Glioblastoma multiforme (GBM) is a highly aggressive malignant tumor, and the most prevalent primary malignant tumor affecting the brain and central nervous system. Recent research indicates that the genetic profile of GBM makes it resistant to drugs and radiation. However, the main obstacle in treating GBM is transporting drugs through the blood-brain barrier (BBB). Albumin is a versatile biomaterial for the synthesis of nanoparticles. The efficiency of albumin-based delivery systems is determined by their ability to improve tumor targeting and accumulation. In this review, we will discuss the prevalence of human glioblastoma and the currently adopted treatment, as well as the structure and some essential functions of the BBB, to transport drugs through this barrier. We will also mention some aspects related to the blood-tumor brain barrier (BTBB) that lead to poor treatment efficacy. The properties and structure of serum albumin were highlighted, such as its role in targeting brain tumors, as well as the progress made until now regarding the techniques for obtaining albumin nanoparticles and their functionalization, in order to overcome the BBB and treat cancer, especially human glioblastoma. The albumin drug delivery nanosystems mentioned in this paper have improved properties and can overcome the BBB to target brain tumors.

Intranasal administration of molecular-gated mesoporous nanoparticles to increase ponatinib delivery to the brain

Background: Glioblastoma is the most common and lethal brain cancer. New treatments are needed. However, the presence of the blood-brain barrier is limiting the development of new treatments directed toward the brain, as it restricts the access and distribution of drugs to the CNS. Materials & methods: In this work, two different nanoparticles (i.e., mesoporous silica nanoparticles and magnetic mesoporous silica nanoparticles) loaded with ponatinib were prepared. Results & conclusion: Both particles were characterized and tested in vitro and in vivo, proving that they are not toxic for blood-brain barrier cells and they increase the amount of drug reaching the brain when administered intranasally in comparison with the results obtained for the free drug.

Recent Advancements in Nanocarrier-assisted Brain Delivery of Phytochemicals Against Neurological Diseases

Despite ongoing advancements in research, the inability of therapeutics to cross the blood-brain barrier (BBB) makes the treatment of neurological disorders (NDs) a challenging task, offering only partial symptomatic relief. Various adverse effects associated with existing approaches are another significant barrier that prompts the usage of structurally diverse phytochemicals as preventive/therapeutic lead against NDs in preclinical and clinical settings. Despite numerous beneficial properties, phytochemicals suffer from poor pharmacokinetic profile which limits their pharmacological activity and necessitates the utility of nanotechnology for efficient drug delivery. Nanocarriers have been shown to be proficient carriers that can enhance drug delivery, bioavailability, biocompatibility, and stability of phytochemicals. We, thus, conducted a meticulous literature survey using several electronic databases to gather relevant studies in order to provide a comprehensive summary about the use of nanocarriers in delivering phytochemicals as a treatment approach for NDs. Additionally, the review highlights the mechanisms of drug transport of nanocarriers across the BBB and explores their potential future applications in this emerging field.

Intrathecal delivery of Macromolecules: Clinical status and emerging technologies

The proximity and association of cerebrospinal fluid (CSF) and the intrathecal (IT) space with deep targets in the central nervous system (CNS) parenchyma makes IT injection an attractive route of administration for brain drug delivery. However, the extent to which intrathecally administered macromolecules are effective in treating neurological diseases is a question of both clinical debate and technological interest. We present the biological, chemical, and physical properties of the intrathecal space that are relevant to drug absorption, distribution, metabolism, and elimination from CSF. We then analyze the evolution of IT drug delivery in clinical trials over the last 20 years. Our analysis revealed that the percentage of clinical trials assessing IT delivery for the delivery of biologics (i.e., macromolecules, cells) for treatment of chronic conditions (e.g., neurodegeneration, cancer, and metabolic diseases) has steadily increased. Clinical trials exploring cell or macromolecular delivery within the IT space have not evaluated engineering technologies, such as depots, particles, or other delivery systems. Recent pre-clinical studies have evaluated IT macromolecule delivery in small animals, postulating that delivery efficacy can be assisted by external medical devices, micro- or nanoparticles, bulk biomaterials, and viral vectors. Further studies are necessary to evaluate the extent to which engineering technologies and IT administration improve CNS targeting and therapeutic outcome.

Exploring the Potential of Aptamers in Targeting Neuroinflammation and Neurodegenerative Disorders: Opportunities and Challenges

Neuroinflammation is the precursor for several neurodegenerative diseases (NDDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). Targeting neuroinflammation has emerged as a promising strategy to address a wide range of CNS pathologies. These NDDs still present significant challenges in terms of limited and ineffective diagnosis and treatment options, driving the need to explore innovative and novel therapeutic alternatives. Aptamers are single-stranded nucleic acids that offer the potential for addressing these challenges through diagnostic and therapeutic applications. In this review, we summarize diagnostic and therapeutic aptamers for inflammatory biomolecules, as well as the inflammatory cells in NDDs. We also discussed the potential of short nucleotides for Aptamer-Based Targeted Brain Delivery through their unique features and modifications, as well as their ability to penetrate the blood-brain barrier. Moreover, the unprecedented opportunities and substantial challenges of using aptamers as therapeutic agents, such as drug efficacy, safety considerations, and pharmacokinetics, are also discussed. Taken together, this review assesses the potential of aptamers as a pioneering approach for target delivery to the CNS and the treatment of neuroinflammation and NDDs.

Intraparenchymal convection enhanced delivery of AAV in sheep to treat Mucopolysaccharidosis IIIC

BACKGROUND

Mucopolysaccharidosis IIIC (MPSIIIC) is one of four Sanfilippo diseases sharing clinical symptoms of severe cognitive decline and shortened lifespan. The missing enzyme, heparan sulfate acetyl-CoA: α-glucosaminide-N-acetyltransferase (HGSNAT), is bound to the lysosomal membrane, therefore cannot cross the blood-brain barrier or diffuse between cells. We previously demonstrated disease correction in MPSIIIC mice using an Adeno-Associated Vector (AAV) delivering HGSNAT via intraparenchymal brain injections using an AAV2 derived AAV-truetype (AAV-TT) serotype with improved distribution over AAV9.

METHODS

Here, intraparenchymal AAV was delivered in sheep using catheters or Hamilton syringes, placed using Brainlab cranial navigation for convection enhanced delivery, to reduce proximal vector expression and improve spread.

RESULTS

Hamilton syringes gave improved AAV-GFP distribution, despite lower vector doses and titres. AAV-TT-GFP displayed moderately better transduction compared to AAV9-GFP but both serotypes almost exclusively transduced neurons. Functional HGSNAT enzyme was detected in 24-37% of a 140g gyrencephalic sheep brain using AAV9-HGSNAT with three injections in one hemisphere.

CONCLUSIONS

Despite variabilities in volume and titre, catheter design may be critical for efficient brain delivery. These data help inform a clinical trial for MPSIIIC.

Antibody drug conjugates for glioblastoma: current progress towards clinical use

INTRODUCTION

Antibody drug conjugates (ADCs) are now a proven therapeutic class for many cancers, combining highly specific targeting with the potency of high effective payloads. This review summarizes the experience with ADCs in brain tumors and examines future paths for their use in these tumors.

AREAS COVERED

This review will cover all the key classes of ADCs which have been tested in primary brain tumors, including commentary on the major trials to date. The efficacy of these trials, as well as their limitations, will put in context of the overall landscape of drug development in brain tumors. Importantly, this review will summarize key learnings and insights from these trials that help provide the basis for rational ways in which these drugs can be effectively and appropriate developed for patients with primary brain tumors.

EXPERT OPINION

ADC development in brain tumors has occurred in two major phases to date. Key learnings from previous trials provide a strong rationale for the continued development of these drugs for primary brain tumors. However, the unique biology of these tumors requires development strategies specifically tailored to maximize their optimal development.

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

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

Assessment of Anti-Alzheimer Pursuit of Jambolan Fruit Extract and/or Choline against AlCl3 Toxicity in Rats

Jambolan fruit extract and choline were investigated for Aluminum tri chloride (AlCl₃)-induced Alzheimer's disease in rats. Thirty-six male "Sprague Dawley" rats weighing (150 ± 10 g) were allocated into six groups; the first group was fed a baseline diet and served as a negative control. Alzheimer's disease (AD) was induced in Group 2 rats by oral administration of AlCl₃ (17 mg/kg body weight) dissolved in distilled water (served as a positive control). Rats in Group 3 were orally supplemented concomitantly with both 500 mg/kg BW of an ethanolic extract of jambolan fruit once daily for 28 days and AlCl₃ (17 mg/kg body weight). Group 4: Rivastigmine (RIVA) aqueous infusion (0.3 mg/kg BW/day) was given orally to rats as a reference drug concomitantly with oral supplementation of AlCl₃ (17 mg/kg body weight) for 28 days. Group 5 rats were orally treated with choline (1.1 g/kg) concomitantly with oral supplementation of AlCl₃ (17 mg/kg body weight). Group 6 was given 500 mg/kg of jambolan fruit ethanolic extract and 1.1 g/kg of choline orally to test for additive effects concurrently with oral supplementation of AlCl₃ (17 mg/kg bw) for 28 days. Body weight gain, feed intake, feed efficiency ratio, and relative brain, liver, kidney, and spleen weight were calculated after the trial. Brain tissue assessment was analyzed for antioxidant/oxidant markers, biochemical analysis in blood serum, a phenolic compound in Jambolan fruits extracted by high-performance liquid chromatography (HPLC), and histopathology of the brain. The results showed that Jambolan fruit extract and choline chloride improved brain functions, histopathology, and antioxidant enzyme activity compared with the positive group. In conclusion, administering jambolan fruit extract and choline can lower the toxic impacts of aluminum chloride on the brain.

Potential Role of Carbon Nanomaterials in the Treatment of Malignant Brain Gliomas

Malignant gliomas are the most common primary brain tumors in adults up to an extent of 78% of all primary malignant brain tumors. However, total surgical resection is almost unachievable due to the considerable infiltrative ability of glial cells. The efficacy of current multimodal therapeutic strategies is, furthermore, limited by the lack of specific therapies against malignant cells, and, therefore, the prognosis of these in patients is still very unfavorable. The limitations of conventional therapies, which may result from inefficient delivery of the therapeutic or contrast agent to brain tumors, are major reasons for this unsolved clinical problem. The major problem in brain drug delivery is the presence of the blood-brain barrier, which limits the delivery of many chemotherapeutic agents. Nanoparticles, thanks to their chemical configuration, are able to go through the blood-brain barrier carrying drugs or genes targeted against gliomas. Carbon nanomaterials show distinct properties including electronic properties, a penetrating capability on the cell membrane, high drug-loading and pH-dependent therapeutic unloading capacities, thermal properties, a large surface area, and easy modification with molecules, which render them as suitable candidates for deliver drugs. In this review, we will focus on the potential effectiveness of the use of carbon nanomaterials in the treatment of malignant gliomas and discuss the current progress of in vitro and in vivo researches of carbon nanomaterials-based drug delivery to brain.

Methylcellulose/agarose hydrogel loaded with short electrospun PLLA/laminin fibers as an injectable scaffold for tissue engineering/3D cell culture model for tumour therapies

This research aimed at designing and fabricating a smart thermosensitive injectable methylcellulose/agarose hydrogel system loaded with short electrospun bioactive PLLA/laminin fibers as a scaffold for tissue engineering applications or 3D cell culture models. Considering ECM-mimicking morphology and chemical composition, such a scaffold is capable of ensuring a hospitable environment for cell adhesion, proliferation, and differentiation. Its viscoelastic properties are beneficial from the practical perspective of minimally invasive materials that are introduced to the body via injection. Viscosity studies showed the shear-thinning character of MC/AGR hydrogels enabling the potential injection ability of highly viscous materials. Injectability tests showed that by tuning the injection rate, even a high amount of short fibers loaded inside of hydrogel could be efficiently injected into the tissue. Biological studies showed the non-toxic character of composite material with excellent viability, attachment, spreading, and proliferation of fibroblasts and glioma cells. These findings indicate that MC/AGR hydrogel loaded with short PLLA/laminin fibers is a promising biomaterial for both tissue engineering applications and 3D tumor culture models.

Transferrin receptor 1 targeted nanomedicine for brain tumor therapy

Achieving effective drug delivery to traverse the blood-brain barrier (BBB) and target tumor cells remains the greatest challenge for brain tumor therapy. Importantly, the overexpressed membrane receptors on the brain endothelial cells, especially transferrin receptor 1 (TfR1), which mediate their ligands/antibodies to overcome the BBB by transcytosis, have been emerging as promising targets for brain tumor therapy. By employing ligands (e.g., transferrin, H-ferritin), antibodies or targeting peptides of TfR1 or aptamers, various functional nano-formulations have been developed in the last decade. These agents showed great potential for the treatment of brain diseases due to their ideal size, high loading capacity, controlled drug release and suitable pharmacokinetics. Herein, we summarize the latest advances on TfR1-targeted nanomedicine for brain tumor therapy. Moreover, we also discuss the strategies of improving stability, targeting ability and accumulation of nano-formulations in brain tumors for better outcomes. In this review, we hope to provide inspiration for the rational design of TfR1-targeted nanomedicine against brain tumors.

Strategic nanocarriers to control neurodegenerative disorders: Concept, challenges, and future perspective

Various neurodegenerative diseases (parkinson, huntington, alzheimer, and amyotrophic lateral sclerosis) are becoming serious global health challenges. Despite various treatment options, successful delivery and effective outcomes have been challenged with several physiological-anatomical barriers, formulation related issues, post-administration hurdles, regulatory constraints, physical hurdles, environmental issues, and safety concern. In the present review, we addressed a brief understanding of pathological and normal condition of blood brain barrier (BBB), rational for brain delivery using nanocarriers, major challenges, advantages of nanomedicine, critical aspects of nanomedicine to translate from bed to clinics, and strategic approaches for improved delivery across BBB. The review addressed various mechanistic perspective for delivery of drug loaded nanocarriers across BBB. Moreover, several reports have been published wherein phytomedicine, exosomes, magnetic nanopartilces, functionalized nanocarriers, cationic nanopartilces, and nano-phytomedicine were investigated for remarkable improvement in neurological disorders. These findings are informative for healthcare professionals, researchers, and scientists working in the domains. The successful application and convincing outcomes of nanomedicines were envisaged with clinical trials conducted on various drugs intended to control neurological disorders (NDs). Conclusively, the review addressed comprehensive findings on various aspects of drug loaded nanocarrier delivery across BBB, considerable risks, potential therapeutic benefits, clinical trial based outcomes, and recent advances followed by future perspectives.

Neuro-nanotechnology: diagnostic and therapeutic nano-based strategies in applied neuroscience

Artificial, de-novo manufactured materials (with controlled nano-sized characteristics) have been progressively used by neuroscientists during the last several decades. The introduction of novel implantable bioelectronics interfaces that are better suited to their biological targets is one example of an innovation that has emerged as a result of advanced nanostructures and implantable bioelectronics interfaces, which has increased the potential of prostheses and neural interfaces. The unique physical-chemical properties of nanoparticles have also facilitated the development of novel imaging instruments for advanced laboratory systems, as well as intelligently manufactured scaffolds and microelectrodes and other technologies designed to increase our understanding of neural tissue processes. The incorporation of nanotechnology into physiology and cell biology enables the tailoring of molecular interactions. This involves unique interactions with neurons and glial cells in neuroscience. Technology solutions intended to effectively interact with neuronal cells, improved molecular-based diagnostic techniques, biomaterials and hybridized compounds utilized for neural regeneration, neuroprotection, and targeted delivery of medicines as well as small chemicals across the blood-brain barrier are all purposes of the present article.

Current approaches to facilitate improved drug delivery to the central nervous system

Although many pharmaceuticals have therapeutic potentials for central nervous system (CNS) diseases, few of these agents have been effectively administered. It is due to the fact that the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSF) restrict them from crossing the brain to exert biological activity. This article reviews the current approaches aiming to improve penetration across these barriers for effective drug delivery to the CNS. These issues are summarized into direct systemic delivery and invasive delivery, including the BBB disruption and convection enhanced delivery. Furthermore, novel drug delivery systems used at the nanoscale, including polymeric nanoparticles, liposomes, nanoemulsions, dendrimers, and micelles are discussed. These nanocarriers could contribute to a breakthrough in the treatment of many different CNS diseases. However, further broadened studies are needed to assess the biocompatibility and safety of these medical devices.