Brain Drug Delivery Research Articles

Development of Imatinib Mesylate-Loaded Liposomes for Nose to Brain Delivery: In Vitro and In Vivo Evaluation

Neurodegenerative diseases like Alzheimer's disease require treatment where it is essential for drug to reach brain. Nose to brain delivery of drugs enables direct transport to brain bypassing blood brain barrier. Imatinib mesylate, an anti-cancer agent, was found to have potential anti-Alzheimer's activity and thus repurposed for the same. However, the drug has severe side effects, poor brain bioavailability which may hinder effective treatment of Alzheimer's disease. In the current work, imatinib mesylate-loaded liposomes were prepared with particle size below 150nm with sustained drug release up to 96h. The liposomal drug formulation was compared with plain drug solution for cytotoxicity on N2a cells and did not show any kind of toxicity at concentrations up to 25μg/mL. The nanocarrier formulation was then evaluated for brain deposition by nose to brain administration in comparison with drug solution in rats. The liposomes effectively improved the brain deposition of drug in brain from formulation compared to pure drug solution as indicated by AUC from in vivo experiments. These results indicate that the nose to brain delivery of liposomal imatinib mesylate improved the drug deposition and residence time in brain compared to drug solution administered through oral and intranasal routes.

High-gravity technology intensified Knoevenagel condensation-Michael addition polymerization of poly (ethylene glycol)-poly (n-butyl cyanoacrylate) for blood-brain barrier delivery

Poly (ethylene glycol)-poly (n-butyl cyanoacrylate) (PEG-PBCA) is a remarkable drug delivery carrier for permeating blood-brain barrier. In this work, a novel high-gravity procedure was reported to intensify Knoevenagel condensation-Michael addition polymerization of PEG-PBCA. A series of PEG-PBCA containing different block ratios were synthesized with narrow molecular weight distribution of polydispersity indexes less than 1.1. Furthermore, the reaction time reduced 60% compared to conventional stirred tank reactor process. Chemical structures of as-prepared polymers were characterized. In vitro drug delivery performance was evaluated. The cytotoxicity of PEG-PBCA to brain microvessel endothelial cells (BMVEC) decreases with the extension of the PEG chain and the shortening of the PBCA chain. The polymer cellular uptake to BMVECs was better after improving hydrophilicity by PEG block. Results of blood-brain barrier permeability demonstrated that medium length of PBCA chain and short PEG chain are favorable for hydrophobic Nile red permeation, while long PEG chain and short PBCA chain are beneficial to delivery water-soluble doxorubicin hydrochloride (Dox). The average apparent permeability coefficient increased 1.7 and 0.25 times than that of raw Nile red and Dox, respectively. High-gravity intensified condensation polymerization should have great potential in brain drug delivery system.

Investigation of therapeutic effect of curcumin α and β glucoside anomers against Alzheimer’s disease by the nose to brain drug delivery

Alzheimer’s disease (AD) is one of the greatest geriatric medicinal challenges of our century and is the main disease leading to dementia. Despite extensive scientific research advances, available disease-modifying treatment strategies remained limited; thus, increasing demand for new drugs. In recent years, medicinal plants attracted attention due to their potential role in dementia. In the present study, α and β anomers of curcumin glucosides (CGs) were synthesized and evaluated for Alzheimer’s treatment. CGs were synthesized by fusion reaction as a novel and easy method with more advantages (high yield, short reaction time, and low chemicals), and the products were characterized using HNMR. Wistar male rats were used to administer different treatments. They divided into control, sham, Alzheimer, and test groups (Alzheimer + α anomer and Alzheimer + β anomer). Animals received normal saline, Scopolamine (1 mg/kg), high dose anomers, scopolamine, and two doses (12.5 and 25 mg/kg) of anomers, respectively, for 10 days. Then the Morris Water Maze (MWM) test was performed on all animals. Finally, the animals’ brains were extracted and homogenized for glutathione, acetylcholine esterase activity, protein carbonyl, and lipid peroxide level detection. The escape latency and the distance towards the hidden platform in Morris water maze in the Alzheimer group were significantly higher than both the control and test groups. Besides, there were no significant differences between sham and control groups in all tests. Both anomers led to a significant increase in glutathione, and acetylcholine levels while they caused a decrease in lipid peroxidation and protein carbonyl levels in brain tissue. It seems that intranasal administration of both anomers positively influenced maze learning in scopolamine receiving subjects. Although both anomers resulted in similar biochemistry tests, a higher dose of β anomer indicated better results than α anomer not only in behavioral tests but also in biochemical tests.

Nanotherapeutics in Neuropathologies: Obstacles, Challenges and Recent Advancements in CNS Targeted Drug Delivery Systems.

Neurology and associated nanotherapeutics are a complex field in terms of therapeutics and neurological disorder complexity. The brain is an intricate appendage and requires more precise embattled treatment for the particular diseases and hence it is a broad scale for developing more targeted drug deliveries. The brain is one of the most inaccessible tissues of the body due to the existence of the blood-brain barrier (BBB), thus delivery of drugs inside the brain is a striking dare and it is also tricky to treat central nervous system (CNS) complications pharmacologically. The therapeutic aspiration is to accomplish the lowest drug meditation in the brain tissues so as to gain favoured therapeutic results. To devastate this obstacle, nanotechnology is engaged in the field of targeted brain drug delivery and neuropathology targeting. These carriers hold myriad abilities as they may augment the drug delivery into the brain by shielding them from degradation and prolonging their transmission in the blood, as well as promoting their transport through the BBB. Nanopharmaceuticals are quickly sprouting as a new avenue that is engaged with the drug-loaded nanocarriers to demonstrate unique physicochemical properties and tiny size range for penetrating the central nervous system. The enchantment behind their therapeutic achievement is the condensed drug dose and inferior toxicity, whereby restricting the therapeutic compound to the specific site. Therefore, in this article, we have tried to recapitulate the advances of the novel scopes for the brain targeted drug delivery for complex neurological disorders.

Clofazimine functionalized polymeric nanoparticles for brain delivery in the tuberculosis treatment

Central nervous system tuberculosis (CNS-TB) is the most severe form of the disease especially due to the inability of therapeutics to cross the blood–brain barrier (BBB). Clofazimine (CFZ) stands out for presenting high in vitro activity against multi-drug resistant strains of Mycobacterium tuberculosis, however, CFZ physicochemical and pharmacokinetics properties limit drug penetration into the CNS and, consequently, its clinical use. The aim of this work was to develop polymeric nanoparticles (NPs) of poly(lactic-co-glycolic acid) (PLGA) and polyethylene glycol (PEG) loaded with CFZ and functionalized with a transferrin receptor (TfR)-binding peptide, aiming brain drug delivery for CNS-TB treatment by the intravenous route. The poor water solubility and high lipophilicity of CFZ was overcome through its entrapment into PLGA-PEG NPs manufactured by both conventional and microfluidic techniques using the nanoprecipitation principle. In vitro studies in brain endothelial hCMEC/D3 cells demonstrated that CFZ incorporation into the NPs was advantageous to reduce drug cytotoxicity. The TfR-binding peptide-functionalized NPs showed superior cell interaction and higher CFZ permeability across hCMEC/D3 cell monolayers compared to the non-functionalized NP control, thus indicating the efficacy of the functionalization strategy on providing CFZ transport through the BBB in vitro. The functionalized NPs demonstrate suitability for CFZ biological administration, suggested with low plasma protein binding, off-target biodistribution and precise delivery of CFZ towards the brain parenchyma.

Nanoparticles approaches in neurodegenerative diseases diagnosis and treatment.

The World Health Organization (WHO) has declared that neurodegenerative diseases will be the biggest health issues of the twenty-first century. Among these, Alzheimer's and Parkinson's diseases can be considered as the most acute incurable neurological diseases. Researchers are studying and developing a new treatment approach that uses nanotechnology to diagnosis and treatment neurodegenerative diseases. This treatment strategy will be used to regress neurodegenerative diseases such as Alzheimer's disease. Alzheimer's disease (AD) is one of the most common forms of reduced brain function, which causes many devastating complications. Current neurodegenerative diseases treatment protocols only help to treat symptoms nevertheless with nanotechnology approaches, can regress nerve cells apoptosis, reduce inflammation, and improve brain drug delivery. In this paper, new nanotechnology methods such as nanobodies, nano-antibodies, and lipid nanoparticles have been investigated. Correspondingly blood-brain barrier drug delivery improvement methods have been suggested.

Recent Advances in the Use of Lipid-Based Nanoparticles Against Glioblastoma Multiforme.

Glioblastoma (GBM) is the most common and aggressive malignant brain tumor in adults. Although the overall incidence is less than 10 per 100,000 individuals, its poor prognosis and low survival rate make GBM a crucial public health issue. The main challenges for GBM treatment are related to tumor location and its complex and heterogeneous biology. In this sense, a broad range of nanoparticles with different sizes, architectures, and surface properties, have been engineered as brain drug delivery systems. Among them, lipid-based nanoparticles, such as liposomes, have been pointed out as promising materials to deliver antitumoral drugs to the central nervous system and thus, to improve brain drug targeting and therapeutic efficiency. Here, we describe the synthesis and general characteristics of lipid-based nanoparticles, as well as evidence in the past 5years regarding their potential use to treat GBM.

Solid lipid nanoparticles: Influence of composition, fabrication methods and problems, in vitro drug release and intranasal administration provide to access olfactory bulb pathway for SLNs

Background: Solid lipid nanoparticles (SLN) have drawn increasing interest in recent years. These nanoparticles are formed from stable or solid lipid mixtures and then stabilized by emulsifiers. As nanoparticles, colloidal particles running in size somewhere in the 10 to 1000 nm range are known. SLN provides fascinating properties, such as minimal scale, massive surface area, high medication piling, correspondence of stages at the interface, and is interested in their ability to enhance drug execution. Main text: This paper provides a description of the choice of ingredients, the effect of lipids and their structure on the formulation, and the various methods of processing SLN. We explain the characteristics of SLN stability and the possibilities of SLN stabilization by lyophilization in this article. The relation between drug absorption and the complexity of SLN dispersions, which involves the existence of other colloidal structures and the physical state of the lipid, is uncommonly considered. We define the possible problems of SLN preparation and performance on the basis of characterization. First, the nasal route was known to accomplish the avoidance of first-pass hepatic metabolism in order to maximize absolute bioavailability, and secondly, the immediate nose-to-brain pathway to enhance the delivery of brain medicines. SLNs have been designated to increase drug permeability through the blood-brain barrier as a drug delivery device (BBB). Conclusion: To sum up, this article gives insight SLNs a colloidal drug carrier places together the compensations of polymeric nanoparticles, SLNs have numerous benefits such as easy incorporation of lipid and lipophilic as well as hydrophilic drugs, suitable physical stability, and available at low cost and easy to manufacture. The nasal route was accepted to exploit first its prevention of the hepatic first-pass metabolism to increase the absolute bioavailability, and second, the direct nose-to-brain pathway to enhance the brain drug delivery. SLNs were chosen as a drug delivery system to improve drug permeability across the blood-brain barrier (BBB) and consequently its brain delivery.

Brain targeting of agomelatine egg lecithin based chitosan coated nanoemulsion

Intranasal drug delivery system has been proposed as an alternative delivery system to target agomelatine (AGO) to the brain and improving its bioavailability. Mucoadhesive egg lecithin nanoemulsions were optimized using D-optimal design and by investigating the effect of four independent variables: oil concentration (A), chitosan concentration (B), type of oil (C) and egg lecithin: oil (D). The responses of globule size, polydispersity index, zeta potential and drug content were evaluated. The optimized agomelatine mucoadhesive nanoemulsion (AGO MNE) with a desirability value of 0.856 was subjected to further investigations for mucoadhesion, in vitro diffusion, transmission electron microscopy and in vivo biodistribution. It showed significantly successful distribution to the brain, the optimized AGO MNE intranasal gave a brain targeting efficiency (BTE) of 278.71% indicating increased drug brain targeting by the nasal route compared with the intravenous route. Additionally, the optimized AGO MNE by intranasal had a direct transport percentage (DTP) of 64.109%, which indicates a significant contribution of the direct nose-to-brain pathway in the brain drug delivery. The study proposed egg lecithin mucoadhesive nanoemulsion as a successful and promising strategy to directly and efficiently deliver drug to the brain.

Alzheimer’s Disease and its Related Dementia Types: A Review on Their Management Via Nanotechnology Based Therapeutic Strategies

Dementia and its related types such as Alzheimer's disease, vascular dementia and mixed dementia belong to brain associated diseases, resulting in long-term progressive memory loss. These diseases are so severe that can affect a person's daily routine. Up to date, treatment of dementia is still an unmet challenge due to their complex pathophysiology and unavailable efficient pharmacological approaches. The use of nanotechnology based pharmaceutical products could possibly improve the management of dementia given that nanocarriers could more efficiently deliver drugs to the brain. The objective of this study is to provide the current nanotechnology based drug delivery systems for the treatment of various dementia types. In addition, the current diagnosis biomarkers for the mentioned dementia types along with their available pharmacological treatment are being discussed. An extensive review of the current nanosystems such as brain drug delivery systems against Alzheimer's disease, vascular dementia and mixed dementia was performed. Moreover, nanotheranostics as possible imaging markers for such dementias were also reported. The field of nanotechnology is quite advantageous for targeting dementia given that nanoscale drug delivery systems easily penetrate the blood brain barrier and circulate in the body for prolonged time. These nanoformulations consist of polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carriers, microemulsions, nanoemulsions, and liquid crystals. The delivery of the nanotherapeutics can be achieved via various administration routes such as transdermal, injectable, oral, and more importantly, through the intranasal route. Nonetheless, the nanocarriers are mostly limited to Alzheimer's disease targeting; thus, nanocarriers for other types of dementia should be developed. To conclude, understanding the mechanism of neurodegeneration and reviewing the current drug delivery systems for Alzheimer's disease and other dementia types are significant for medical and pharmaceutical society to produce efficient therapeutic choices and novel strategies based on multifunctional and biocompatible nanocarriers, which can deliver the drug sufficiently into the brain.

Recent advances on drug delivery nanocarriers for cerebral disorders

Pharmacotherapies for brain disorders are generally faced with obstacles from the blood-brain barrier (BBB). There are a variety of drug delivery systems that have been put forward to cross or bypass the BBB with the access to the central nervous system. Brain drug delivery systems have benefited greatly from the development of nanocarriers, including lipids, polymers and inorganic materials. Consequently, various kinds of brain drug delivery nano-systems have been established, such as liposomes, polymeric nanoparticles (PNPs), nanomicelles, nanohydrogels, dendrimers, mesoporous silica nanoparticles and magnetic iron oxide nanoparticles. The characteristics of their carriers and preparations usually differ from each other, as well as their transportation mechanisms into intracerebral lesions. In this review, different types of brain drug delivery nanocarriers are classified and summarized, especially their significant achievements, to present several recommendations and directions for future strategies of cerebral delivery.

Focused Ultrasound-Enhanced Delivery of Intranasally Administered Anti-Programmed Cell Death-Ligand 1 Antibody to an Intracranial Murine Glioma Model.

Immune checkpoint inhibitors have great potential for the treatment of gliomas; however, their therapeutic efficacy has been partially limited by their inability to efficiently cross the blood–brain barrier (BBB). The objective of this study was to evaluate the capability of focused-ultrasound-mediated intranasal brain drug delivery (FUSIN) in achieving the locally enhanced delivery of anti-programmed cell death-ligand 1 antibody (aPD-L1) to the brain. Both non-tumor mice and mice transcranially implanted with GL261 glioma cells at the brainstem were used in this study. aPD-L1 was labeled with a near-infrared fluorescence dye (IRDye 800CW) and administered to mice through the nasal route to the brain, followed by focused ultrasound sonication in the presence of systemically injected microbubbles. FUSIN enhanced the accumulation of aPD-L1 at the FUS-targeted brainstem by an average of 4.03- and 3.74-fold compared with intranasal (IN) administration alone in the non-tumor mice and glioma mice, respectively. Immunohistochemistry staining found that aPD-L1 was mainly located within the perivascular spaces after IN delivery, while FUSIN further enhanced the penetration depth and delivery efficiency of aPD-L1 to the brain parenchyma. The delivered aPD-L1 was found to be colocalized with the tumor cells after FUSIN delivery to the brainstem glioma. These findings suggest that FUSIN is a promising technique to enhance the delivery of immune checkpoint inhibitors to gliomas.

Focused ultrasound-mediated intranasal brain drug delivery technique (FUSIN)

The blood-brain barrier (BBB) is the major obstacle for brain drug delivery and limits the treatment options for central nervous system diseases. To circumvent the BBB, we introduce focused ultrasound-mediated intranasal brain drug delivery (FUSIN). FUSIN utilizes the nasal route for direct nose-to-brain drug administration, bypassing the BBB and minimizing systemic exposure to the major organs, such as heart, lung, liver, and kidney [1]. It also uses transcranial ultrasound energy focused at a targeted brain region to induce microbubble cavitation, enhancing the transport of intranasally administered agents at the FUS-targeted brain location. FUSIN is unique because it can achieve noninvasive and localized brain drug delivery with minimized systemic toxicity to other major organs. The goal of this paper is to provide a detailed protocol for FUSIN delivery to the mouse brain.•FUSIN delivery utilizes the nose-to-brain pathway for brain drug delivery.•FUSIN utilizes FUS combined with microbubble to significantly enhance the delivery efficiency of intranasally administered drugs to the FUS targeted brain regions.•FUSIN achieves efficient brain delivery with minimized systemic exposure in the major organs.

From blood to brain: blood cell-based biomimetic drug delivery systems

Brain drug delivery remains a major difficulty for several challenges including the blood–brain barrier, lesion spot targeting, and stability during circulation. Blood cells including erythrocytes, platelets, and various subpopulations of leukocytes have distinct features such as long-circulation, natural targeting, and chemotaxis. The development of biomimetic drug delivery systems based on blood cells for brain drug delivery is growing fast by using living cells, membrane coating nanotechnology, or cell membrane-derived nanovesicles. Blood cell-based vehicles are superior delivery systems for their engineering feasibility and versatile delivery ability of chemicals, proteins, and all kinds of nanoparticles. Here, we focus on advances of blood cell-based biomimetic carriers for from blood to brain drug delivery and discuss their translational challenges in the future.

Advanced Nanosystems for Clinical Translation

Advanced Nanosystems for Clinical Translation

Mechanisms of Sound-Induced Opening of the Blood-Brain Barrier.

The blood-brain barrier (BBB) poses a significant challenge for drug delivery to the brain. The limitations of our knowledge about the nature of BBB explain the slow progress in the therapy of brain diseases and absence of methods for drug delivery to the brain in clinical practice. Here, we show that the BBB opens for high-molecular-weight compounds after exposure to loud sound (100dB 370Hz) in rats. The role of stress induced by loud sound and the systemic and molecular mechanisms behind it are discussed in the framework of the BBB. This opens an informative platform for novel fundamental knowledge about the nature of BBB and for the development of a noninvasive brain drug delivery technology.

Nose-to-brain delivery of drug nanocrystals by using Ca2+ responsive deacetylated gellan gum based in situ-nanogel

The objective of this study is to use a carbohydrate polymer deacetylated gellan gum (DGG) as matrix to design nanocrystals based intranasal in situ gel (IG) for nose-to -brain delivery of drug. The harmine nanocrystals (HAR-NC) as model drug were prepared by coupling homogenization and spray-drying technology. The HAR-NC was redispersed in the (DGG) solutions and formed the ionic-triggered harmine nanocrystals based in situ gel (HAR-NC-IG). The crystal state of HAR remained unchanged during the homogenization and spray-drying. And the HAR-NC-IG with 0.5% DGG exhibited excellent in situ-gelation ability, water retention property and in vitro release behavior. The bioavailability in brain of intranasal HAR-NC-IG were 25-fold higher than that of oral HAR-NC, which could be attributed to nanosizing effect of HAR-NC and bioadhesive property of DGG triggered by nasal fluid. And the HAR-NC-IG could significantly inhibit the expression of acetylcholinesterase (AchE) and increase the content of acetylcholin (ACh) in brain compared with those of reference formulations (p < 0.01). The DGG based nanocrystals-in situ gel was a promising carrier for nose-to-brain delivery of poorly soluble drug, which could prolong the residence time and improve the bioavailability of poorly soluble drugs in brain.

Phenomenon of music-induced opening of the blood-brain barrier in healthy mice.

Music plays a more important role in our life than just being an entertainment. For example, it can be used as an anti-anxiety therapy of human and animals. However, the unsafe listening of loud music triggers hearing loss in millions of young people and professional musicians (rock, jazz and symphony orchestra) owing to exposure to damaging sound levels using personal audio devices or at noisy entertainment venues including nightclubs, discotheques, bars and concerts. Therefore, it is important to understand how loud music affects us. In this pioneering study on healthy mice, we discover that loud rock music below the safety threshold causes opening of the blood-brain barrier (OBBB), which plays a vital role in protecting the brain from viruses, bacteria and toxins. We clearly demonstrate that listening to loud music during 2 h in an intermittent adaptive regime is accompanied by delayed (1 h after music exposure) and short-lasting to (during 1–4 h) OBBB to low and high molecular weight compounds without cochlear and brain impairments. We present the systemic and molecular mechanisms responsible for music-induced OBBB. Finally, a revision of our traditional knowledge about the BBB nature and the novel strategies in optimizing of sound-mediated methods for brain drug delivery are discussed.

Electrophysiological effects of polyethylene glycol modified gold nanoparticles on mouse hippocampal neurons

Gold nanoparticles (AuNPs) can cross the blood brain barrier, thus can be used as nanocarriers in brain drug delivery. However, the effect of bare and polyethylene glycol-modified (PEGylated) AuNPs on normal neural function has not been extensively investigated. In this study, bioelectrical properties of neuronal functions of male BALB/c mice were explored ex vivo and in vivo by using 5 nm bare AuNPs and PEGylated AuNPs. Electrophysiological properties of neurons from hippocampal CA1 region sections were recorded by patch clamp method. Ex vivo, firing rate of action and membrane potentials in response to negative current stimuli significantly altered only after bare AuNP exposure compared to control (p < 0.05). After in vivo injections, anxiety levels of animals were similar. Amplitude of action potentials reduced only in bare AuNP group (p < 0.05). In conclusion, excitability of hippocampal neurons is increasing with bare AuNP exposure, and PEGylation might be more biocompatible for medical applications.

Microbubble formulation influences inflammatory response to focused ultrasound exposure in the brain

Focused ultrasound and microbubble (FUS + MB)-mediated blood–brain barrier (BBB) permeability enhancement can facilitate targeted brain-drug delivery. While controlling the magnitude of BBB permeability enhancement is necessary to limit tissue damage, little work has attempted to decouple these concepts. This work investigated the relationship between BBB permeability enhancement and the relative transcription of inflammatory mediators 4 h following sonication. Three microbubble formulations, Definity, BG8774, and MSB4, were compared, with the dose of each formulation normalized to gas volume. While changes in the transcription of key proinflammatory mediators, such as Il1b, Ccl2, and Tnf, were correlated to the magnitude of BBB permeability enhancement, these correlations were not independent of microbubble formulation; microbubble size distribution may play an important role, as linear regression analyses of BBB permeability magnitude versus differential gene expression for these proinflammatory mediators revealed significantly greater slopes for MSB4, a monodisperse microbubble with mean diameter of 4 μm, compared to Definity or BG8774, both polydisperse microbubbles with mean diameters below 2 μm. Additionally, the function of an acoustic feedback control algorithm, based on the detection threshold of ultraharmonic emissions, was assessed. While this control strategy was effective in limiting both wideband emissions and red blood cell extravasation, microbubble formulation was found to influence the magnitude of BBB leakage and correlations to acoustic emissions. This work demonstrates that while the initial magnitude of FUS + MB-mediated BBB permeability enhancement has a clear influence on the subsequent inflammatory responses, microbubble characteristics influence these relationships and must also be considered.