Opening of the blood-brain barrier with an unfocused ultrasound device in rabbits

2013 ◽  
Vol 119 (4) ◽  
pp. 887-898 ◽  
Author(s):  
Kevin Beccaria ◽  
Michael Canney ◽  
Lauriane Goldwirt ◽  
Christine Fernandez ◽  
Clovis Adam ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Blood Brain Barrier ◽  
Ultrasonic Transducer ◽  
Brain Barrier ◽  
Single Element ◽  
Blood Brain ◽  
The Us ◽  
The Brain ◽  
Bbb Opening

Object The blood-brain barrier (BBB) is a major impediment to the intracerebral diffusion of drugs used in the treatment of gliomas. Previous studies have demonstrated that pulsed focused ultrasound (US) in conjunction with a microbubble contrast agent can be used to open the BBB. To apply the US-induced opening of the BBB in clinical practice, the authors designed an innovative unfocused US device that can be implanted in the skull and used to transiently and repeatedly open the BBB during a standard chemotherapy protocol. The goal of this preliminary work was to study the opening of the BBB induced by the authors' small unfocused US transducer and to evaluate the effects of the sonications on brain parenchyma. Methods Craniectomy was performed in 16 healthy New Zealand White rabbits; epidural application of a single-element planar ultrasonic transducer operating at 1 MHz was then used with a pulse-repetition frequency of 1 Hz, pulse lengths of 10–35 msec, in situ acoustic pressure levels of 0.3–0.8 MPa, and sonication for 60–120 seconds. SonoVue was intravenously injected during the US applications, and opening of the BBB was determined by detecting extravasation of Evans blue dye (EBD) in brain tissues, quantitative measurement of EBD with UV-visible spectrophotometry, and contrast enhancement after Gd injection in 4.7-T MRI. A histological study was performed to determine adverse effects. Results An opening of the BBB was observed over a large extent of the US beam in the brain corresponding to in situ pressures of greater than 0.2 MPa. The BBB opening observed was highly significant for both EBD (p < 0.01) and MRI Gd enhancement (p < 0.0001). The BBB opening was associated with minor adverse effects that included perivascular red blood cell extravasations that were less than 150 μm in size and not visible on MR images. Moderate edema was visible on FLAIR sequences and limited to the extent of the sonication field. Conclusions The results demonstrate that the BBB can be opened in large areas of the brain in rabbits with lowpower, pulsed, and unfocused US with limited damage to healthy tissue.

scholarly journals Claudin-5 binder enhances focused ultrasound-mediated opening in an in vitro blood-brain barrier model

2021 ◽  
Author(s):  
Ratneswary Sutharsan ◽  
Liyu Chen ◽  
Jonathan LF Lee ◽  
Esteban Cruz ◽  
Tishila Palliyaguru ◽  
...  
Keyword(s):  
Cell Line ◽  
Blood Brain Barrier ◽  
Focused Ultrasound ◽  
Brain Barrier ◽  
Sodium Fluorescein ◽  
General Strategy ◽  
Blood Brain ◽  
Barrier Opening ◽  
The Brain ◽  
Bbb Opening

Rationale: The blood-brain barrier (BBB) while functioning as a gatekeeper of the brain, impedes cerebral drug delivery. An emerging technology to overcome this limitation is focused ultrasound (FUS). When FUS interacts with intravenously injected microbubbles (FUS+MB), the BBB opens, transiently allowing the access of therapeutic agents into the brain. However, the ultrasound parameters need to be tightly tuned: when the acoustic pressure is too low there is no opening, and when it is too high, bleeds can occur. We therefore asked whether BBB permeability can be increased by combining FUS+MB with a second modality such that in a clinical setting lower acoustic pressures could be potentially used. Methods: Given that FUS achieves BBB opening by the disruption of tight junction (TJ) proteins such as claudin-5 of brain endothelial cells, we generated a stable MDCK II cell line (eGFP-hCldn5-MDCK II) that expresses fluorescently tagged human claudin-5. Two claudin-5 binders, mC5C2 (a peptide) and cCPEm (a truncated form of an enterotoxin), that have been reported previously to weaken the barrier, were synthesized and assessed for their abilities to enhance the permeability of cellular monolayers. We then performed a comparative analysis of single and combination treatments. Results: We successfully generated a novel cell line that formed functional monolayers as validated by an increased transendothelial electrical resistance (TEER) reading and a low (< 0.2%) permeability to sodium fluorescein (376 Da). We found that the binders exerted a time- and concentration-dependent effect on BBB opening when incubated over an extended period, whereas FUS+MB caused a rapid barrier opening followed by recovery after 12 hours within the tested pressure range. Importantly, preincubation with cCPEm prior to FUS+MB treatment resulted in greater barrier opening compared to either FUS+MB or cCPEm alone as measured by reduced TEER values and an increased permeability to fluorescently labelled 40 kDa dextran (FD40). Conclusion: The data suggest that pre-incubation with clinically suitable binders to TJ proteins may be a general strategy to facilitate safer and more effective ultrasound-mediated BBB opening in cellular and animal systems and potentially also for the treatment of human diseases of the brain.

scholarly journals Ultrasound-induced opening of the blood-brain barrier to enhance temozolomide and irinotecan delivery: an experimental study in rabbits

2016 ◽  
Vol 124 (6) ◽  
pp. 1602-1610 ◽  
Author(s):  
Kevin Beccaria ◽  
Michael Canney ◽  
Lauriane Goldwirt ◽  
Christine Fernandez ◽  
Julie Piquet ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Ultrasound Contrast Agent ◽  
Ultra Performance Liquid Chromatography ◽  
Brain Barrier ◽  
Control Group ◽  
Tumor Treatment ◽  
Blood Brain ◽  
Ultrasound Sonication ◽  
Bbb Opening

OBJECT The blood-brain barrier (BBB) limits the intracerebral penetration of drugs and brain tumor treatment efficacy. The effect of ultrasound-induced BBB opening on the intracerebral concentration of temozolomide (TMZ) and irinotecan (CPT-11) was assessed. METHODS This study was performed using 34 healthy New Zealand rabbits. Half had unilateral BBB opening, and half served as controls. Sonications were performed by pulsing a 1.05-MHz planar ultrasound transducer with a duty cycle of 2.5% and an in situ acoustic pressure level of 0.6 MPa after injection of a microbubble ultrasound contrast agent. Drugs were injected either 5 minutes before (ChemoPreUS) or 15 minutes after (ChemoPostUS) the ultrasound sonication. The plasma and intracerebral concentrations of both drugs were quantified using ultra-performance liquid chromatography. RESULTS The mean intracerebral tissue-to-plasma drug concentration ratio in the control hemispheres was 34% for TMZ and 2% for CPT-11. After BBB opening, these values increased by up to 21% for TMZ and up to 178% for CPT-11. Intracerebral concentrations of drugs were enhanced in regions where the BBB was opened compared with the contralateral hemisphere (p < 0.01 and p < 0.0001 for CPT-11, p = 0.02 and p = 0.03 for TMZ, in ChemoPreUS and ChemoPostUS, respectively) and compared with the control group (p < 0.001 and p < 0.0001 for CPT-11, p < 0.01 and p = 0.02 for TMZ, in ChemoPreUS and ChemoPostUS, respectively). The intracerebral distribution of drugs was heterogeneous, depending on the distance from the ultrasound source. CONCLUSIONS Ultrasound-induced opening of the BBB significantly enhances the intracerebral concentration of both TMZ and CPT-11 in rabbits.

scholarly journals Impact of P-Glycoprotein Inhibition and Lipopolysaccharide Administration on Blood-Brain Barrier Transport of Colistin in Mice

2010 ◽  
Vol 55 (2) ◽  
pp. 502-507 ◽  
Author(s):  
Liang Jin ◽  
Jian Li ◽  
Roger L. Nation ◽  
Joseph A. Nicolazzo
Keyword(s):  
Blood Brain Barrier ◽  
Systemic Inflammation ◽  
Brain Barrier ◽  
Brain Uptake ◽  
P Glycoprotein ◽  
Blood Brain ◽  
Colistin Sulfate ◽  
The Brain ◽  
Concentration Ratios

ABSTRACTThe aim of this study was to investigate the factors limiting the blood-brain barrier (BBB) transport of colistin in healthy mice and to assess the impact of systemic inflammation on the transport of this antibiotic across the BBB. Colistin sulfate (40 mg/kg) was administered subcutaneously to Swiss outbred mice as single and multiple doses to determine any relationship between brain uptake and plasma concentrations of colistin. To assess the effect of P-glycoprotein (P-gp) on BBB transport, colistin sulfate (5 mg/kg) was concomitantly administered intravenously with PSC833 or GF120918 (10 mg/kg). Systemic inflammation was induced by three intraperitoneal injections of lipopolysaccharide (LPS; 3 mg/kg), and BBB transport of colistin was subsequently measured following subcutaneous administration and by anin situbrain perfusion. The brain uptake of colistin was low following single and multiple subcutaneous doses, with brain-to-plasma concentration ratios ranging between 0.021 and 0.037, and this was not significantly enhanced by coadministration of GF120918 or PSC833 (P> 0.05). LPS significantly increased the brain uptake of subcutaneously administered colistin with area under the brain concentration time curve (AUCbrain) values of 11.7 ± 2.7 μg·h/g and 4.0 ± 0.3 μg·h/g for LPS- and saline-treated mice, respectively (mean ± standard deviation). Similarly,in situperfusion of colistin led to higher antibiotic brain concentrations in LPS-treated animals than in saline-treated animals, with colistin brain-to-perfusate concentration ratios of 0.019 ± 0.001 and 0.014 ± 0.001, respectively. This study demonstrates that the BBB transport of colistin is negligible in healthy mice; however, brain concentrations of colistin can be significantly enhanced during systemic inflammation, as might be observed in infected patients.

scholarly journals Dynamic Study of Blood–Brain Barrier Closure after its Disruption using Ultrasound: A Quantitative Analysis

2012 ◽  
Vol 32 (10) ◽  
pp. 1948-1958 ◽  
Author(s):  
Benjamin Marty ◽  
Benoit Larrat ◽  
Maxime Van Landeghem ◽  
Caroline Robic ◽  
Philippe Robert ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Focal Point ◽  
Molecular Size ◽  
Brain Barrier ◽  
Hydrodynamic Diameter ◽  
Power Ultrasound ◽  
Blood Brain ◽  
Ultrasound Sonication ◽  
The Brain ◽  
Bbb Opening

Delivery of therapeutic or diagnostic agents to the brain is majorly hindered by the blood–brain barrier (BBB). Recently, many studies have demonstrated local and transient disruption of the BBB using low power ultrasound sonication combined with intravascular microbubbles. However, BBB opening and closure mechanisms are poorly understood, especially the maximum gap that may be safely generated between endothelial cells and the duration of opening of the BBB. Here, we studied BBB opening and closure under magnetic resonance (MR) guidance in a rat model. First, MR contrast agents (CA) of different hydrodynamic diameters (1 to 65 nm) were employed to estimate the largest molecular size permissible across the cerebral tissues. Second, to estimate the duration of the BBB opening, the CA were injected at various times post-BBB disruption (12 minutes to 24 hours). A T1 mapping strategy was developed to assess CA concentration at the ultrasound (US) focal point. Based on our experimental data and BBB closure modeling, a calibration curve was obtained to compute the half closure time as a function of CA hydrodynamic diameter. These findings and the model provide an invaluable basis for optimal design and delivery of nanoparticles to the brain.

scholarly journals THER-11. PEPTIDE-MEDIATED PERMEABILIZATION OF THE BLOOD-BRAIN BARRIER IMPROVES DRUG DELIVERY TO BRAIN METASTASIS

2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i13-i13
Author(s):  
Synnøve Nymark Aasen ◽  
Heidi Espedal ◽  
Christopher Holte ◽  
Olivier Keunen ◽  
Tine Veronika Karlsen ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Blood Brain Barrier ◽  
Plasma Membranes ◽  
Combined Treatment ◽  
Brain Barrier ◽  
Therapeutic Window ◽  
Dce Mri ◽  
Blood Brain ◽  
The Brain ◽  
Bbb Opening

Abstract BACKGROUND: Melanoma patients have a high risk of developing brain metastases, which is associated with a poor prognosis. The blood-brain barrier (BBB) inhibits sufficient drug delivery into metastatic lesions. We investigated the ability of a synthetic peptide (K16ApoE) to permeabilize the BBB for more effective drug treatment. METHODS: DCE-MRI was performed to study the therapeutic window of BBB opening facilitated by K16ApoE. In vivoand in vitroassays were used to determine K16ApoE toxicity and also to obtain mechanistic insight into its action on the BBB. The therapeutic impact of K16ApoE on melanoma metastases was determined together with dabrafenib, which is otherwise known not to cross an intact BBB. RESULTS: DCE-MRI exhibited an effective K16ApoE-mediated BBB opening for up to 1h. Mechanistic studies displayed a dose-dependent effect of K16ApoE caused by induction of endocytosis. At higher concentrations, the peptide also showed unspecific disturbances on plasma membranes. Combined treatment with K16ApoE and dabrafenib reduced the brain metastatic burden in mice compared to dabrafenib. We also showed by PET/CT that the peptide facilitated the delivery of compounds up to 150 kDa into the brain. CONCLUSIONS: We demonstrate a transient opening of the BBB, caused by K16ApoE, that facilitates improved drug-delivery into the brain. This improves the efficacy of drugs that otherwise do not cross the intact BBB.

scholarly journals Focused ultrasound mediated blood–brain barrier opening is safe and feasible in a murine pontine glioma model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zachary K. Englander ◽  
Hong-Jian Wei ◽  
Antonios N. Pouliopoulos ◽  
Ethan Bendau ◽  
Pavan Upadhyayula ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Motor Function ◽  
Focused Ultrasound ◽  
Weight Lifting ◽  
Brain Barrier ◽  
Single Element ◽  
Pontine Glioma ◽  
Blood Brain ◽  
Glioma Model ◽  
Bbb Opening

AbstractDrug delivery in diffuse intrinsic pontine glioma is significantly limited by the blood-brain barrier (BBB). Focused ultrasound (FUS), when combined with the administration of microbubbles can effectively open the BBB permitting the entry of drugs across the cerebrovasculature into the brainstem. Given that the utility of FUS in brainstem malignancies remains unknown, the purpose of our study was to determine the safety and feasibility of this technique in a murine pontine glioma model. A syngeneic orthotopic model was developed by stereotactic injection of PDGF-B+PTEN−/−p53−/− murine glioma cells into the pons of B6 mice. A single-element, spherical-segment 1.5 MHz ultrasound transducer driven by a function generator through a power amplifier was used with concurrent intravenous microbubble injection for tumor sonication. Mice were randomly assigned to control, FUS and double-FUS groups. Pulse and respiratory rates were continuously monitored during treatment. BBB opening was confirmed with gadolinium-enhanced MRI and Evans blue. Kondziela inverted screen testing and sequential weight lifting measured motor function before and after sonication. A subset of animals were treated with etoposide following ultrasound. Mice were either sacrificed for tissue analysis or serially monitored for survival with daily weights. FUS successfully caused BBB opening while preserving normal cardiorespiratory and motor function. Furthermore, the degree of intra-tumoral hemorrhage and inflammation on H&E in control and treated mice was similar. There was also no difference in weight loss and survival between the groups (p > 0.05). Lastly, FUS increased intra-tumoral etoposide concentration by more than fivefold. FUS is a safe and feasible technique for repeated BBB opening and etoposide delivery in a preclinical pontine glioma model.

Effects of Intravascular Contrast Media on Blood-Brain Barrier

1987 ◽  
Vol 28 (3) ◽  
pp. 329-333 ◽  
Author(s):  
Å. Aulie Michelet
Keyword(s):  
Computed Tomography ◽  
Adverse Effects ◽  
Contrast Media ◽  
Blood Brain Barrier ◽  
Trypan Blue ◽  
Brain Barrier ◽  
Severe Damage ◽  
Blood Brain ◽  
Ionic Contrast ◽  
The Brain

The effects upon the rabbit blood-brain barrier after intracarotid injection of two non-ionic contrast media, iopentol (a monomer) and iodixanol (a dimer) were compared. Iothalamate and iohexol were used as reference substances. 99Tcm-DTPA, 125I-HSA and Trypsin blue were used as tracers in order to demonstrate various degrees of damage to the barrier. Injection of iothalamate led to large extravasation of 99Tcm-DTPA, 125I-HSA and Trypan blue which means severe damage of the blood-brain barrier. Injection of iopentol and iohexol resulted in some extravasation of all three tracers used, whereas injection of iodixanol only led to extravasation of the small molecule tracer 99Tcm-DTPA demonstrating minor changes of the barrier. At computed tomography of the brain with intravascular contrast medium enhancement it is safer to use iodixanol than iothalamate. Iodixanol is expected to cause even less adverse effects to the brain after intraarterial injection than iopentol and iohexol.

RADT-17. FOCUSED ULTRASOUND MEDIATED BLOOD–BRAIN BARRIER OPENING IS SAFE AND FEASIBLE CONCURRENT WITH AND ADJUVANT TO A CLINICAL RADIATION SCHEME FOR BRAINSTEM DMG

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi44-vi45
Author(s):  
Masih Tazhibi ◽  
Nicholas McQuillan ◽  
Hong-Jian Wei ◽  
Antonios Pouliopoulos ◽  
Ethan Bendau ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Focused Ultrasound ◽  
Motor Coordination ◽  
Weight Lifting ◽  
Brain Barrier ◽  
Single Element ◽  
Blood Brain ◽  
Dismal Prognosis ◽  
Bbb Opening ◽  
Radiation Scheme

Abstract Diffuse midline gliomas (DMG) are pediatric tumors with dismal prognosis. When these tumors emerge in the brainstem, there exists no feasible method of surgical resection or systemic intervention, making ionizing radiation the sole therapeutic avenue to date. However, radiotherapy (RT) provides only marginal survival benefit as the topographically diffuse and highly infiltrative tumors spread in areas in which the blood-brain barrier (BBB) is relatively intact. Focused ultrasound (FUS) with intravenous microbubbles provides a compelling solution, transiently and non-invasively opening the BBB to allow drug delivery across the cerebrovasculature. Nonetheless, it remains unclear whether FUS can be safely administered at the brainstem in patients receiving RT. Therefore, the goal of this study was to assess the safety and feasibility of FUS administered concurrent with and adjuvant to a clinical hypofractionated radiation scheme for brainstem DMG. Non-tumor bearing B6 albino mice were randomly assorted into control, RT, FUS, and RT+FUS groups. Mice designated RT+FUS received 39Gy/13fx (hypofractionated RT scheme) to the brainstem with two sessions of FUS approximately 1 week apart. A single-element, spherical-segment FUS transducer driven by a function generator through a power amplifier was used with concomitant microbubble injection to sonicate the brainstem. Magnetic resonance imaging (MRI) was used to confirm BBB opening and cardiopulmonary measures were recorded throughout sonication. Vitals were assessed daily, and all treatment animals underwent Kondziela inverted screen testing and sequential weight lifting to assess brainstem-related strength and motor coordination deficits. In both FUS and RT+FUS mice, MRI confirmed brainstem BBB opening and subsequent closure within 96 hours. Mouse weights were stable, with slight drops (mean=5.5%) following FUS that resolved within three days. No attenuation in cardiorespiratory, strength, and motor coordination measurements was observed from FUS. FUS is a safe and feasible technique for brainstem BBB opening concurrent with and adjuvant to clinical hypofractionated RT.

scholarly journals Consistent opening of the blood brain barrier using focused ultrasound with constant intravenous infusion of microbubble agent

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Norman A. Lapin ◽  
Kirt Gill ◽  
Bhavya R. Shah ◽  
Rajiv Chopra
Keyword(s):  
Blood Brain Barrier ◽  
Focused Ultrasound ◽  
Brain Barrier ◽  
Mri Contrast ◽  
Intravenous Injections ◽  
Blood Brain ◽  
Target Sites ◽  
The Brain ◽  
Microbubble Agent ◽  
Bbb Opening

Abstract The blood brain barrier (BBB) is a major obstacle to the delivery of therapeutics to the brain. Focused ultrasound (FUS) in combination with microbubbles can non-invasively open the BBB in a targeted manner. Bolus intravenous injections of microbubbles are standard practice, but dynamic influx and clearance mechanisms prevent delivery of a uniform dose with time. When multiple targets are selected for sonication in a single treatment, uniform serum concentrations of microbubbles are important for consistent BBB opening. Herein, we show that bubble infusions were able to achieve consistent BBB opening at multiple target sites. FUS exposures were conducted with different Definity microbubble concentrations at various acoustic pressures. To quantify the effects of infusion on BBB opening, we calculated the MRI contrast enhancement rate. When infusions were performed at rates of 7.2 µl microbubbles/kg/min or below, we were able to obtain consistent BBB opening without injury at all pressures. However, when infusion rates exceeded 20 µl/kg/min, signs of injury occurred at pressures from 0.39 to 0.56 MPa. When compared to bolus injections, a bubble infusion offers a more controlled and consistent approach to multi-target BBB disruption.

scholarly journals The Inhibitory Effect of Kakkonto, Japanese Traditional (Kampo) Medicine, on Brain Penetration of Oseltamivir Carboxylate in Mice with Reduced Blood-Brain Barrier Function

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Kousuke Ohara ◽  
Shinji Oshima ◽  
Nanami Fukuda ◽  
Yumiko Ochiai ◽  
Ayumi Maruyama ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Blood Brain Barrier ◽  
Therapeutic Effect ◽  
Barrier Function ◽  
Clinical Effectiveness ◽  
Inhibitory Effect ◽  
Brain Barrier ◽  
Oseltamivir Carboxylate ◽  
Blood Brain ◽  
The Brain

Oseltamivir phosphate (OP) is used to treat influenza virus infections. However, its use may result in central nervous system (CNS) adverse effects. In Japan, OP is used with Kampo formulations to improve clinical effectiveness. We evaluated the potential for using Kampo formulations to reduce CNS adverse effects by quantifying the CNS distribution of oseltamivir and its active metabolite oseltamivir carboxylate (OC) when administered with maoto and kakkonto. We administered lipopolysaccharide (LPS) by intraperitoneal injection to C57BL/6 mice to reduce blood-brain barrier function. Saline, maoto, and kakkonto were administered orally at the same time as LPS. OP was orally administered 4 hours after the last LPS injection and the migration of oseltamivir and OC was examined. Additionally, we examined the brain distribution of OC following intravenous administration. Changes in OC concentrations in the brain suggest that, in comparison to LPS-treated control mice, both Kampo formulations increased plasma levels of OC, thereby enhancing its therapeutic effect. Additionally, our findings suggest kakkonto may not only improve the therapeutic effect of oseltamivir but also reduce the risk of CNS-based adverse effects. Considering these findings, it should be noted that administration of kakkonto during periods of inflammation has led to increased OAT3 expression.

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