scholarly journals Novel delivery methods bypassing the blood-brain and blood-tumor barriers

2015 ◽  
Vol 38 (3) ◽  
pp. E10 ◽  
Author(s):  
Benjamin K. Hendricks ◽  
Aaron A. Cohen-Gadol ◽  
James C. Miller
Keyword(s):  
Primary Brain Tumor ◽  
Pathological Process ◽  
Therapeutic Interventions ◽  
Delivery Methods ◽  
Ongoing Research ◽  
Functional Capabilities ◽  
Blood Brain ◽  
Natural Protection ◽  
The Brain ◽  
Brain Homeostasis

Glioblastoma (GBM) is the most common primary brain tumor and carries a grave prognosis. Despite years of research investigating potentially new therapies for GBM, the median survival rate of individuals with this disease has remained fairly stagnant. Delivery of drugs to the tumor site is hampered by various barriers posed by the GBM pathological process and by the complex physiology of the blood-brain and blood–cerebrospinal fluid barriers. These anatomical and physiological barriers serve as a natural protection for the brain and preserve brain homeostasis, but they also have significantly limited the reach of intraparenchymal treatments in patients with GBM. In this article, the authors review the functional capabilities of the physical and physiological barriers that impede chemotherapy for GBM, with a specific focus on the pathological alterations of the blood-brain barrier (BBB) in this disease. They also provide an overview of current and future methods for circumventing these barriers in therapeutic interventions. Although ongoing research has yielded some potential options for future GBM therapies, delivery of chemotherapy medications across the BBB remains elusive and has limited the efficacy of these medications.

scholarly journals Molecular Mechanisms of Drug Resistance in Glioblastoma

2021 ◽  
Vol 22 (12) ◽  
pp. 6385
Author(s):  
Maya A. Dymova ◽  
Elena V. Kuligina ◽  
Vladimir A. Richter
Keyword(s):  
Drug Resistance ◽  
Brain Tumor ◽  
Molecular Mechanisms ◽  
Primary Brain Tumor ◽  
Therapeutic Resistance ◽  
Molecular Characteristics ◽  
Blood Brain ◽  
Conventional Radiation ◽  
The Brain ◽  
Made In

Glioblastoma multiforme (GBM) is the most common and fatal primary brain tumor, is highly resistant to conventional radiation and chemotherapy, and is not amenable to effective surgical resection. The present review summarizes recent advances in our understanding of the molecular mechanisms of therapeutic resistance of GBM to already known drugs, the molecular characteristics of glioblastoma cells, and the barriers in the brain that underlie drug resistance. We also discuss the progress that has been made in the development of new targeted drugs for glioblastoma, as well as advances in drug delivery across the blood–brain barrier (BBB) and blood–brain tumor barrier (BBTB).

scholarly journals Modulating the Blood-Brain Barrier by Light Stimulation of Molecular-Targeted Nanoparticles

2020 ◽  
Author(s):  
Xiaoqing Li ◽  
Vamsidhara Vemireddy ◽  
Qi Cai ◽  
Hejian Xiong ◽  
Peiyuan Kang ◽  
...  
Keyword(s):  
Tight Junction ◽  
Tight Junctions ◽  
Blood Brain Barrier ◽  
Therapeutic Interventions ◽  
Brain Barrier ◽  
Light Stimulation ◽  
Targeted Nanoparticles ◽  
Blood Brain ◽  
The Brain ◽  
Stimulation Of

AbstractThe blood-brain barrier (BBB) tightly regulates the entry of molecules into the brain by tight junctions that seals the paracellular space and receptor-mediated transcytosis. It remains elusive to selectively modulate these mechanisms and to overcome BBB without significant neurotoxicity. Here we report that light stimulation of tight junction-targeted plasmonic nanoparticles selectively opens up the paracellular route to allow diffusion through the compromised tight junction and into the brain parenchyma. The BBB modulation does not impair vascular dynamics and associated neurovascular coupling, or cause significant neural injury. It further allows antibody and adeno-associated virus delivery into local brain regions. This novel method offers the first evidence of selectively modulating BBB tight junctions and opens new avenues for therapeutic interventions in the central nervous system.One Sentence SummaryGentle stimulation of molecular-targeted nanoparticles selectively opens up the paracellular pathway and allows macromolecules and gene therapy vectors into the brain.

scholarly journals Structural, Molecular, and Functional Alterations of the Blood-Brain Barrier during Epileptogenesis and Epilepsy: A Cause, Consequence, or Both?

2020 ◽  
Vol 21 (2) ◽  
pp. 591 ◽  
Author(s):  
Wolfgang Löscher ◽  
Alon Friedman
Keyword(s):  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Defense Mechanism ◽  
Extracellular Fluid ◽  
Cell Types ◽  
Therapeutic Interventions ◽  
Brain Barrier ◽  
Transport Systems ◽  
Blood Brain ◽  
The Brain

The blood-brain barrier (BBB) is a dynamic, highly selective barrier primarily formed by endothelial cells connected by tight junctions that separate the circulating blood from the brain extracellular fluid. The endothelial cells lining the brain microvessels are under the inductive influence of neighboring cell types, including astrocytes and pericytes. In addition to the anatomical characteristics of the BBB, various specific transport systems, enzymes and receptors regulate molecular and cellular traffic across the BBB. While the intact BBB prevents many macromolecules and immune cells from entering the brain, following epileptogenic brain insults the BBB changes its properties. Among BBB alterations, albumin extravasation and diapedesis of leucocytes from blood into brain parenchyma occur, inducing or contributing to epileptogenesis. Furthermore, seizures themselves may modulate BBB functions, permitting albumin extravasation, leading to activation of astrocytes and the innate immune system, and eventually modifications of neuronal networks. BBB alterations following seizures are not necessarily associated with enhanced drug penetration into the brain. Increased expression of multidrug efflux transporters such as P-glycoprotein likely act as a ‘second line defense’ mechanism to protect the brain from toxins. A better understanding of the complex alterations in BBB structure and function following seizures and in epilepsy may lead to novel therapeutic interventions allowing the prevention and treatment of epilepsy as well as other detrimental neuro-psychiatric sequelae of brain injury.

scholarly journals Function and Biomarkers of the Blood-Brain Barrier in a Neonatal Germinal Matrix Haemorrhage Model

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1677
Author(s):  
Erik Axel Andersson ◽  
Eridan Rocha-Ferreira ◽  
Henrik Hagberg ◽  
Carina Mallard ◽  
Carl Joakim Ek
Keyword(s):  
Blood Brain Barrier ◽  
Brain Injuries ◽  
Therapeutic Interventions ◽  
Brain Barrier ◽  
Germinal Matrix ◽  
Blood Brain ◽  
Old Rats ◽  
The Brain ◽  
Tracer Experiments ◽  
Junction Proteins

Germinal matrix haemorrhage (GMH), caused by rupturing blood vessels in the germinal matrix, is a prevalent driver of preterm brain injuries and death. Our group recently developed a model simulating GMH using intrastriatal injections of collagenase in 5-day-old rats, which corresponds to the brain development of human preterm infants. This study aimed to define changes to the blood-brain barrier (BBB) and to evaluate BBB proteins as biomarkers in this GMH model. Regional BBB functions were investigated using blood to brain 14C-sucrose uptake as well as using biotinylated BBB tracers. Blood plasma and cerebrospinal fluids were collected at various times after GMH and analysed with ELISA for OCLN and CLDN5. The immunoreactivity of BBB proteins was assessed in brain sections. Tracer experiments showed that GMH produced a defined region surrounding the hematoma where many vessels lost their integrity. This region expanded for at least 6 h following GMH, thereafter resolution of both hematoma and re-establishment of BBB function occurred. The sucrose experiment indicated that regions somewhat more distant to the hematoma also exhibited BBB dysfunction; however, BBB function was normalised within 5 days of GMH. This shows that GMH leads to a temporal dysfunction in the BBB that may be important in pathological processes as well as in connection to therapeutic interventions. We detected an increase of tight-junction proteins in both CSF and plasma after GMH making them potential biomarkers for GMH.

scholarly journals Brain endothelial LRP1 maintains blood–brain barrier integrity

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Steffen E. Storck ◽  
Magdalena Kurtyka ◽  
Claus U. Pietrzik
Keyword(s):  
Blood Brain Barrier ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Brain Barrier ◽  
Blood Proteins ◽  
Glycoprotein P ◽  
Blood Brain ◽  
Density Lipoprotein Receptor ◽  
The Brain ◽  
Brain Homeostasis

AbstractThe entry of blood-borne molecules into the brain is restricted by the blood–brain barrier (BBB). Various physical, transport and immune properties tightly regulate molecule movement between the blood and the brain to maintain brain homeostasis. A recent study utilizing a pan-endothelial, constitutive Tie2-Cre showed that paracellular passage of blood proteins into the brain is governed by endocytic and cell signaling protein low-density lipoprotein receptor–related protein 1 (LRP1). Taking advantage of conditional Slco1c1-CreERT2 specific to CNS endothelial cells and choroid plexus epithelial cells we now supplement previous results and show that brain endothelial Lrp1 ablation results in protease-mediated tight junction degradation, P-glycoprotein (P-gp) reduction and a loss of BBB integrity.

scholarly journals Nanotherapeutics Overcoming the Blood-Brain Barrier for Glioblastoma Treatment

2021 ◽  
Vol 12 ◽  
Author(s):  
Lin Tang ◽  
Yicheng Feng ◽  
Sai Gao ◽  
Qingchun Mu ◽  
Chaoyong Liu
Keyword(s):  
Drug Delivery ◽  
Blood Brain Barrier ◽  
Primary Brain Tumor ◽  
Brain Barrier ◽  
Great Promise ◽  
Current Standard ◽  
Blood Brain ◽  
Average Survival ◽  
Main Barrier ◽  
The Brain

Glioblastoma (GBM) is the most common malignant primary brain tumor with a poor prognosis. The current standard treatment regimen represented by temozolomide/radiotherapy has an average survival time of 14.6 months, while the 5-year survival rate is still less than 5%. New therapeutics are still highly needed to improve the therapeutic outcome of GBM treatment. The blood-brain barrier (BBB) is the main barrier that prevents therapeutic drugs from reaching the brain. Nanotechnologies that enable drug delivery across the BBB hold great promise for the treatment of GBM. This review summarizes various drug delivery systems used to treat glioma and focuses on their approaches for overcoming the BBB to enhance the accumulation of small molecules, protein and gene drugs, etc. in the brain.

scholarly journals Blood-Brain Delivery Methods Using Nanotechnology

Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 269 ◽  
Author(s):  
Daniel Teleanu ◽  
Cristina Chircov ◽  
Alexandru Grumezescu ◽  
Adrian Volceanov ◽  
Raluca Teleanu
Keyword(s):  
Multiple Sclerosis ◽  
Carbon Nanotubes ◽  
Drug Development ◽  
Brain Cancer ◽  
Therapeutic Agents ◽  
Brain Delivery ◽  
Delivery Methods ◽  
Selective Permeability ◽  
Blood Brain ◽  
The Brain

Pathologies of the brain, of which brain cancer, Alzheimer’s disease, Parkinson’s disease, stroke, and multiple sclerosis, are some of the most prevalent, and that presently are poorly treated due to the difficulties associated with drug development, administration, and targeting to the brain. The existence of the blood-brain barrier, a selective permeability system which acts as a local gateway against circulating foreign substances, represents the key challenge for the delivery of therapeutic agents to the brain. However, the development of nanotechnology-based approaches for brain delivery, such as nanoparticles, liposomes, dendrimers, micelles, and carbon nanotubes, might be the solution for improved brain therapies.

scholarly journals The Roles of the Microbiome in Alzheimer’s Disease

2021 ◽  
Vol 2 (1) ◽  
pp. 159-167
Author(s):  
Zahin Hafiz ◽  
Moina Malek ◽  
William Ju
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Brain Barrier ◽  
Metabolic Diseases ◽  
The Other ◽  
Therapeutic Interventions ◽  
Brain Barrier ◽  
Therapeutic Implications ◽  
Blood Brain ◽  
The Brain

The gut and the brain are in constant communication in a complex network known as the brain-gut axis. A growing body of research has found links between the brain-gut axis and Alzheimer’s Disease (AD). In this review, we will explore how the mammalian microbiome affects neuroinflammation and increases the permeability of the blood brain barrier in the context of AD. Research shows that the microbiome is associated with neuroinflammation in AD, which is presumably caused by the secretion of cytokines from specialized cells of the brain - microglia and astrocytes. On the other hand, metabolic diseases, caused by microbiota dysbiosis, can increase the permeability of the blood brain barrier. In addition, its higher permeability can allow blood plasma components to enter brain tissue and further develop AD pathology. Findings of the current research have tremendous therapeutic implications. Researchers have speculated whether the therapeutic modification of gut microbiota, through the use of antibiotics and probiotics, may show improvement in AD patients. Our understanding of the pathways and mechanisms involved in the brain-gut axis and AD is still very limited and requires further research before clinical and therapeutic interventions can occur.

scholarly journals Astrocytes: new targets of melanocortin 4 receptor actions

2013 ◽  
Vol 51 (2) ◽  
pp. R33-R50 ◽  
Author(s):  
Carla Caruso ◽  
Lila Carniglia ◽  
Daniela Durand ◽  
Teresa N Scimonelli ◽  
Mercedes Lasaga
Keyword(s):  
Energy Homeostasis ◽  
Therapeutic Interventions ◽  
Neuroprotective Activity ◽  
Brain Physiology ◽  
Melanocortin 4 Receptor ◽  
Anti Inflammatory ◽  
Apoptotic Effects ◽  
The Brain ◽  
Excessive Activation ◽  
Brain Homeostasis

Astrocytes exert a wide variety of functions with paramount importance in brain physiology. After injury or infection, astrocytes become reactive and they respond by producing a variety of inflammatory mediators that help maintain brain homeostasis. Loss of astrocyte functions as well as their excessive activation can contribute to disease processes; thus, it is important to modulate reactive astrocyte response. Melanocortins are peptides with well-recognized anti-inflammatory and neuroprotective activity. Although melanocortin efficacy was shown in systemic models of inflammatory disease, mechanisms involved in their effects have not yet been fully elucidated. Central anti-inflammatory effects of melanocortins and their mechanisms are even less well known, and, in particular, the effects of melanocortins in glial cells are poorly understood. Of the five known melanocortin receptors (MCRs), only subtype 4 is present in astrocytes. MC4R has been shown to mediate melanocortin effects on energy homeostasis, reproduction, inflammation, and neuroprotection and, recently, to modulate astrocyte functions. In this review, we will describe MC4R involvement in anti-inflammatory, anorexigenic, and anti-apoptotic effects of melanocortins in the brain. We will highlight MC4R action in astrocytes and discuss their possible mechanisms of action. Melanocortin effects on astrocytes provide a new means of treating inflammation, obesity, and neurodegeneration, making them attractive targets for therapeutic interventions in the CNS.

scholarly journals Mechanisms of Invasion in Glioblastoma: Extracellular Matrix, Ca2+ Signaling, and Glutamate

2021 ◽  
Vol 15 ◽  
Author(s):  
Jae-Seon So ◽  
Hyeono Kim ◽  
Kyung-Seok Han
Keyword(s):  
Extracellular Matrix ◽  
Brain Tumor ◽  
Primary Brain Tumor ◽  
Therapeutic Interventions ◽  
Signaling Cascades ◽  
Migration And Invasion ◽  
Cellular Mechanisms ◽  
Brain Tumor Cells ◽  
Complete Surgical Resection ◽  
The Brain

Glioblastoma (GBM) is the most common and malignant form of primary brain tumor with a median survival time of 14–16 months in GBM patients. Surgical treatment with chemotherapy and radiotherapy may help increase survival by removing GBM from the brain. However, complete surgical resection to eliminate GBM is almost impossible due to its high invasiveness. When GBM cells migrate to the brain, they interact with various cells, including astrocytes, neurons, endothelial cells, and the extracellular matrix (ECM). They can also make their cell body shrink to infiltrate into narrow spaces in the brain; thereby, they can invade regions of the brain and escape from surgery. Brain tumor cells create an appropriate microenvironment for migration and invasion by modifying and degrading the ECM. During those processes, the Ca2+ signaling pathway and other signaling cascades mediated by various ion channels contribute mainly to gene expression, motility, and invasion of GBM cells. Furthermore, GBM cells release glutamate, affecting migration via activation of ionotropic glutamate receptors in an autocrine manner. This review focuses on the cellular mechanisms of glioblastoma invasion and motility related to ECM, Ca2+ signaling, and glutamate. Finally, we discuss possible therapeutic interventions to inhibit invasion by GBM cells.

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