scholarly journals [18F]2-Fluoro-2-Deoxy-Sorbitol PET Imaging for Quantitative Monitoring of Enhanced Blood–Brain Barrier Permeability Induced by Focused Ultrasound

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1752
Author(s):  
Gaëlle Hugon ◽  
Sébastien Goutal ◽  
Ambre Dauba ◽  
Louise Breuil ◽  
Benoit Larrat ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Pet Imaging ◽  
Focused Ultrasound ◽  
Chemical Reduction ◽  
Imaging Techniques ◽  
Brain Barrier ◽  
Blood Brain ◽  
Bbb Permeability ◽  
The Impact

Focused ultrasound in combination with microbubbles (FUS) provides an effective means to locally enhance the delivery of therapeutics to the brain. Translational and quantitative imaging techniques are needed to noninvasively monitor and optimize the impact of FUS on blood–brain barrier (BBB) permeability in vivo. Positron-emission tomography (PET) imaging using [18F]2-fluoro-2-deoxy-sorbitol ([18F]FDS) was evaluated as a small-molecule (paracellular) marker of blood–brain barrier (BBB) integrity. [18F]FDS was straightforwardly produced from chemical reduction of commercial [18F]2-deoxy-2-fluoro-D-glucose. [18F]FDS and the invasive BBB integrity marker Evan’s blue (EB) were i.v. injected in mice after an optimized FUS protocol designed to generate controlled hemispheric BBB disruption. Quantitative determination of the impact of FUS on the BBB permeability was determined using kinetic modeling. A 2.2 ± 0.5-fold higher PET signal (n = 5; p < 0.01) was obtained in the sonicated hemisphere and colocalized with EB staining observed post mortem. FUS significantly increased the blood-to-brain distribution of [18F]FDS by 2.4 ± 0.8-fold (VT; p < 0.01). Low variability (=10.1%) of VT values in the sonicated hemisphere suggests reproducibility of the estimation of BBB permeability and FUS method. [18F]FDS PET provides a readily available, sensitive and reproducible marker of BBB permeability to noninvasively monitor the extent of BBB disruption induced by FUS in vivo.

scholarly journals EXTH-02. THE BLOOD BRAIN BARRIER (BBB) PERMEABILITY IS ALTERED BY TUMOR TREATING FIELDS (TTFIELDS) IN VIVO

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi82-vi82 ◽  
Author(s):  
Ellina Schulz ◽  
Almuth F Kessler ◽  
Ellaine Salvador ◽  
Dominik Domröse ◽  
Malgorzata Burek ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Dce Mri ◽  
Tumor Treating Fields ◽  
Blood Brain ◽  
Vessel Structure ◽  
Bbb Permeability ◽  
The Brain

Abstract OBJECTIVE For glioblastoma patients Tumor Treating Fields (TTFields) have been established as adjuvant therapy. The blood brain barrier (BBB) tightly controls the influx of the majority of compounds from blood to brain. Therefore, the BBB may block delivery of drugs for treatment of brain tumors. Here, the influence of TTFields on BBB permeability was assessed in vivo. METHODS Rats were treated with 100 kHz TTFields for 72 h and thereupon i.v. injected with Evan’s Blue (EB) which directly binds to Albumin. To evaluate effects on BBB, EB was extracted after brain homogenization and quantified. In addition, cryosections of rat brains were prepared following TTFields application. The sections were stained for tight junction proteins Claudin-5 and Occludin and for immunoglobulin G (IgG) to assess vessel structure. Furthermore, serial dynamic contrast-enhanced DCE-MRI with Gadolinium contrast agent was performed before and after TTFields application. RESULTS TTFields application significantly increased the EB accumulation in the rat brain. In TTFields-treated rats, the vessel structure became diffuse compared to control cryosections of rat brains; Claudin 5 and Occludin were delocalized and IgG was found throughout the brain tissue. Serial DCE-MRI demonstrated significantly increased accumulation of Gadolinium in the brain, observed directly after 72 h of TTFields application. The effect of TTFields on the BBB disappeared 96 h after end of treatment and no difference in contrast enhancement between controls and TTFields treated animals was detectable. CONCLUSION By altering BBB integrity and permeability, application of TTFields at 100 kHz may have the potential to deliver drugs to the brain, which are unable to cross the BBB. Utilizing TTFields to open the BBB and its subsequent recovery could be a clinical approach of drug delivery for treatment of brain tumors and other diseases of the central nervous system. These results will be further validated in clinical Trials.

scholarly journals Blood-brain barrier opening for facilitating drug delivery in neurological and neurodegenerative diseases in non-human primates

2018 ◽  
Author(s):  
Elisa E. Konofagou
Keyword(s):  
Neurodegenerative Diseases ◽  
Blood Brain Barrier ◽  
Focused Ultrasound ◽  
Neurological Diseases ◽  
Brain Barrier ◽  
Blood Brain ◽  
Therapeutic Molecules ◽  
After Cancer ◽  
Large Animals

After cancer and heart disease, neurodegenerative diseases, such as Alzheimer's, Parkinson's, multiple sclerosis (MS), amythrophic lateral sclerosis (ALS), and neurological diseases take more lives each year than any other illness. Although great progress has been made in recent years toward understanding of central nervous system (CNS) diseases, few effective treatments and no cures are currently available. This is mainly because the blood-brain barrier (BBB) limits the delivery of the vast majority of systemically-administered drugs available to treat those diseases. The underlying hypothesis of this study is that delivery of therapeutic molecules is safe and effective through the blood-brain barrier (BBB) using Focused Ultrasound (FUS) in large animals in vivo. Our preliminary results have shown that the FUS technique can induce BBB opening entirely noninvasively, selectively and be monitored with MRI at sub-millimeter resolution in vivo. The specific aims are therefore to: 1) build a MRcompatible system for FUS targeting and monitoring in the MRI system; 2) test and demonstrate delivery of neurotrophic factors to the hippocampus and putamen of monkeys; 3) test and demonstrate delivery of inhibitors to the visual cortex of monkeys; and 4) assess the safety of the FUS method in monkeys.

scholarly journals [18F]2-fluoro-2-deoxy-sorbitol PET Imaging for Quantitative Estimation of Blood-brain Barrier Permeability in vivo

2021 ◽  
Author(s):  
Gaelle Hugon ◽  
Sébastien Goutal ◽  
Ambre Dauba ◽  
Louise Breuil ◽  
Alexandra Winkeler ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Transfer Rate ◽  
Right Hemisphere ◽  
Quantitative Estimation ◽  
Kinetic Modelling ◽  
Chemical Reduction ◽  
Fold Increase ◽  
Brain Barrier ◽  
Blood Brain

Abstract Purpose The non-transported and non-metabolized sorbitol derivative [18F]2-fluoro-2-deoxy-sorbitol ([18F]FDS) can be straightforwardly obtained from chemical reduction of commercial [18F]2-deoxy-2-fluoro-D-glucose. [18F]FDS was evaluated as a small-molecule (paracellular) marker of blood-brain barrier (BBB) integrity for PET. Methods Five mice underwent focused ultrasound (FUS) to generate spatially controlled BBB disruption in the right hemisphere. PET kinetics of [18F]FDS in each brain hemisphere were described by a 1-tissue compartment model using an image-derived input function. Results BBB disruption resulted in a 2.4±0.8-fold increase in the brain distribution (VT, p<0.01) of [18F]FDS. Enhanced brain uptake was associated with an increase in the influx transfer rate K1 (+1.4±0.7-fold, p<0.05) and a decrease in the efflux transfer rate k2 (-1.7±0.4-fold, p<0.01). Conclusion Thanks to the quantitative performance of PET compared with other neuroimaging techniques, [18F]FDS PET and kinetic modelling provides a readily available and sensitive method for non-invasive determination of different levels of BBB permeability in vivo.

scholarly journals Comparative vulnerability of PET radioligands to partial inhibition of P-glycoprotein at the blood-brain barrier: A criterion of choice?

2021 ◽  
pp. 0271678X2110454
Author(s):  
Louise Breuil ◽  
Solène Marie ◽  
Sébastien Goutal ◽  
Sylvain Auvity ◽  
Charles Truillet ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Pet Imaging ◽  
Brain Barrier ◽  
Maximal Response ◽  
Half Maximum ◽  
Partial Inhibition ◽  
P Glycoprotein ◽  
Blood Brain

Only partial deficiency/inhibition of P-glycoprotein (P-gp, ABCB1) function at the blood-brain barrier (BBB) is likely to occur in pathophysiological situations or drug-drug interactions. This raises questions regarding the sensitivity of available PET imaging probes to detect moderate changes in P-gp function at the living BBB. In vitro, the half-maximum inhibitory concentration (IC50) of the potent P-gp inhibitor tariquidar in P-gp-overexpressing cells was significantly different using either [11C]verapamil (44 nM), [11C] N-desmethyl-loperamide (19 nM) or [11C]metoclopramide (4 nM) as substrate probes. In vivo PET imaging in rats showed that the half-maximum inhibition of P-gp-mediated efflux of [11C]metoclopramide, achieved using 1 mg/kg tariquidar ( in vivo IC50 = 82 nM in plasma), increased brain exposure by 2.1-fold for [11C]metoclopramide (p < 0.05, n = 4) and 2.4-fold for [11C]verapamil (p < 0.05, n = 4), whereby cerebral uptake of the “avid” substrate [11C] N-desmethyl-loperamide was unaffected (p > 0.05, n = 4). This comparative study points to differences in the “vulnerability” to P-gp inhibition among radiolabeled substrates, which were apparently unrelated to their “avidity” (maximal response to P-gp inhibition). Herein, we advocate that partial inhibition of transporter function, in addition to complete inhibition, should be a primary criterion of evaluation regarding the sensitivity of radiolabeled substrates to detect moderate but physiologically-relevant changes in transporter function in vivo.

scholarly journals P11.28 Alteration of blood brain barrier (BBB) permeability by Tumor Treating Fields (TTFields) in vivo

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii49-iii49
Author(s):  
A F Keßler ◽  
E Salvador ◽  
D Domröse ◽  
M Burek ◽  
C Tempel Brami ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Dce Mri ◽  
Tumor Treating Fields ◽  
Blood Brain ◽  
Vessel Structure ◽  
Bbb Permeability ◽  
The Brain

Abstract BACKGROUND Alternating electric fields with intermediate frequency (100 - 300 kHz) and low intensity (1 - 3 V/cm), known as Tumor Treating Fields (TTFields), have been established as a novel adjuvant therapy for glioblastoma (GBM) patients. The blood brain barrier (BBB) tightly controls the influx of the majority of compounds from blood to brain. Due to this regulation, the BBB may block delivery of drugs for treatment of brain tumors, in particular GBM. In this study, we investigated the influence of TTFields on BBB permeability in vivo. MATERIAL AND METHODS For determination of BBB permeability, rats were treated with 100 kHz TTFields for 72 h. At the end of treatment, rats were i.v. injected with Evan′s Blue (EB), which binds Albumin (~70 kDa) upon injection to the blood. EB was extracted after brain homogenization and quantified at 610 nm. In addition, cryosections of rat brains were prepared following TTFields application at 100 kHz for 72 h, and sections were stained for Claudin 5, Occludin and immunoglobulin G (IgG) to assess vessel structure. Moreover, serial dynamic contrast-enhanced DCE-MRI with Gadolinium contrast agent (Gd) was performed before and after TTFields application. RESULTS In vivo, the EB accumulation in the brain was significantly increased by application of TTFields to the rat head. Claudin 5 and Occludin staining was visible in vessel endothelial cells and localized at the cells’ edges in control cryosections of rat brains. In TTFields-treated rats, the vessel structure became diffuse; Claudin 5 and Occludin were delocalized and IgG was found throughout the brain tissue and not solely inside the vessels, as it is normally the case. Serial DCE-MRI demonstrated significantly increased accumulation of Gd in the brain, detected directly after 72 h of TTFields application. 96 h after end of TTFields treatment the effect on the BBB disappeared and no difference in contrast enhancement between controls and TTFields treated animals was observable. CONCLUSION Application of TTFields at 100 kHz could have the potential to deliver drugs to the brain, which normally are unable to cross the BBB by altering BBB integrity and permeability. Utilizing TTFields to open the BBB and its subsequent recovery, as demonstrated by the data presented herein, could lead to a clinical approach of drug delivery for treatment of malignant brain tumors and other diseases of the central nervous system. These results will be further validated in clinical trials.

scholarly journals Yuzu and Hesperidin Ameliorate Blood-Brain Barrier Disruption during Hypoxia via Antioxidant Activity

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 843
Author(s):  
Bo Kyung Lee ◽  
Soo-Wang Hyun ◽  
Yi-Sook Jung
Keyword(s):  
Endothelial Cell ◽  
Blood Brain Barrier ◽  
Cell Model ◽  
Antioxidant Properties ◽  
Brain Barrier ◽  
Blood Brain ◽  
In Vivo Animal Model ◽  
Bbb Permeability

Yuzu and its main component, hesperidin (HSP), have several health benefits owing to their anti-inflammatory and antioxidant properties. We examined the effects of yuzu and HSP on blood–brain barrier (BBB) dysfunction during ischemia/hypoxia in an in vivo animal model and an in vitro BBB endothelial cell model, and also investigated the underlying mechanisms. In an in vitro BBB endothelial cell model, BBB permeability was determined by measurement of Evans blue extravasation in vivo and in vitro. The expression of tight junction proteins, such as claudin-5 and zonula occludens-1 (ZO-1), was detected by immunochemistry and western blotting, and the reactive oxygen species (ROS) level was measured by 2′7′-dichlorofluorescein diacetate intensity. Yuzu and HSP significantly ameliorated the increase in BBB permeability and the disruption of claudin-5 and ZO-1 in both in vivo and in vitro models. In bEnd.3 cells, yuzu and HSP were shown to inhibit the disruption of claudin-5 and ZO-1 during hypoxia, and the protective effects of yuzu and HSP on claudin-5 degradation seemed to be mediated by Forkhead box O 3a (FoxO3a) and matrix metalloproteinase (MMP)-3/9. In addition, well-known antioxidants, trolox and N-acetyl cysteine, significantly attenuated the BBB permeability increase, disruption of claudin-5 and ZO-1, and FoxO3a activation during hypoxia, suggesting that ROS are important mediators of BBB dysfunction during hypoxia. Collectively, these results indicate that yuzu and HSP protect the BBB against dysfunction via maintaining integrity of claudin-5 and ZO-1, and these effects of yuzu and HSP appear to be a facet of their antioxidant properties. Our findings may contribute to therapeutic strategies for BBB-associated neurodegenerative diseases.

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