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Fletcher SMP, Zhang Y, Chisholm A, Martinez S, McDannold N. The impact of pulse repetition frequency on microbubble activity and drug delivery during focused ultrasound-mediated blood-brain barrier opening. Phys Med Biol 2024; 69:145002. [PMID: 38914104 DOI: 10.1088/1361-6560/ad5b47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 06/24/2024] [Indexed: 06/26/2024]
Abstract
Objective.Pulsed focused ultrasound (FUS) can deliver therapeutics to the brain by using intravenous microbubbles (MBs) to open the blood-brain barrier (BBB). MB emissions indicate treatment outcomes, like BBB opening (harmonics) and damage (broadband). Typically, a pulse repetition frequency (PRF) of 1 Hz is used, but the effect of PRF on MBs is not fully understood. We investigated the effect of PRF on MB activity and tracer delivery.Approach.The effect of PRF (0.125, 0.25, 0.5, 1, and 2 Hz) on MB activity was monitored through harmonic and wideband emissions during FUS sonications of the rat brain at 274.3 kHz. BBB opening was quantified through fluorescence imaging to estimate the concentration of Trypan Blue (TB) dye following a 75-pulse FUS exposure for PRFs of 1 and 0.25 Hz.Main results.At a fixed acoustic pressure, the percentage change in maximum harmonic amplitude compared to the control (PRF = 1 Hz) decreased with increasing PRF, with a median change of 73.8% at 0.125 Hz and -38.3% at 2 Hz. There was no difference in the pressure threshold for broadband emissions between PRFs of 0.25 and 1 Hz. PRF = 0.25 Hz, led to a 68.2% increase in the mean concentration of TB measured after FUS, with a 53.9% increase in the mean harmonic sum, compared with PRF = 1 Hz. Harmonic emissions-based control at PRF = 0.25 Hz yielded similar TB delivery, with less damage at histology, compared with 1 Hz.Significance.For a fixed number of FUS pulses, reducing the PRF was shown to increase the magnitude of harmonic emissions and TB delivery, but not the threshold for broadband emissions. While further research is necessary to understand the mechanisms involved, these results may be useful to improve clinical safety margins and sensitivity to detecting small harmonic signals from cavitating MBs.
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Affiliation(s)
- Stecia-Marie P Fletcher
- Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States of America
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
| | - Yongzhi Zhang
- Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States of America
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
| | - Amanda Chisholm
- Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States of America
| | - Sofia Martinez
- Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States of America
| | - Nathan McDannold
- Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States of America
- Department of Radiology, Harvard Medical School, Boston, MA, United States of America
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2
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Oeffinger BE, Stanczak M, Lepore AC, Eisenbrey JR, Wheatley MA. Determining Ultrasound Parameters for Bursting Polymer Microbubbles for Future Use in Spinal Cord Injury. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:888-897. [PMID: 38519360 DOI: 10.1016/j.ultrasmedbio.2024.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 02/14/2024] [Accepted: 02/22/2024] [Indexed: 03/24/2024]
Abstract
OBJECTIVE We believe our poly(lactic acid) (PLA) microbubbles are well suited for therapeutic delivery to spinal cord injury (SCI) using ultrasound-triggered bursting. We investigated the feasibility of clinical ultrasound bursting in situ, the optimal bursting parameters in vitro and the loading and release of a model bio-active DNA. METHODS Microbubbles were tested using clinical ultrasound in a rat cadaver SCI model. Burst pressure thresholds were determined using the change in enhancement after ultrasound exposure. Resonance frequency, acoustic enhancement, sizing and morphology were evaluated by comparing two microbubble porogens, ammonium carbonate and ammonium carbamate. Oligonucleotides were loaded into the shell and released using the found optimized ultrasound bursting parameters. RESULTS In situ imaging and bursting were successful. In vitro bursting thresholds using frequencies 1, 2.25 and 5 MHz were identified between peak negative pressures 0.2 and 0.5 MPa, believed to be safe for spinal cord. The pressure threshold decreased with decreasing frequencies. PLA bursting was optimized near the resonance frequency of 2.5 to 3.0 MHz using 2.25 MHz and not at lower frequencies. PLA microbubbles, initially with a mean size of approximately 2 µm, remained in one piece, collapsed to between 0.5 and 1 µm and did not fragment. Significantly more oligonucleotide was released after ultrasound bursting of loaded microbubbles. Microbubble-sized debris was detected when using ammonium carbamate, leading to inaccurate microbubble concentration measurements. CONCLUSION PLA microbubbles made with ammonium carbonate and burst at appropriate parameters have the potential to safely improve intrathecal therapeutic delivery to SCI using targeted ultrasound.
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Affiliation(s)
- Brian E Oeffinger
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Maria Stanczak
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Angelo C Lepore
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical Collage at Thomas Jefferson University, Philadelphia, PA, USA
| | - John R Eisenbrey
- Department of Radiology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Margaret A Wheatley
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA.
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Xu R, Treeby BE, Martin E. Safety Review of Therapeutic Ultrasound for Spinal Cord Neuromodulation and Blood-Spinal Cord Barrier Opening. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:317-331. [PMID: 38182491 DOI: 10.1016/j.ultrasmedbio.2023.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 01/07/2024]
Abstract
New focused ultrasound spinal cord applications have emerged, particularly those improving therapeutic agent delivery to the spinal cord via blood-spinal cord barrier opening and the neuromodulation of spinal cord tracts. One hurdle in the development of these applications is safety. It may be possible to use safety trends from seminal and subsequent works in focused ultrasound to guide the development of safety guidelines for spinal cord applications. We collated data from decades of pre-clinical studies and illustrate a clear relationship between damage, time-averaged spatial peak intensity and exposure duration. This relationship suggests a thermal mechanism underlies ultrasound-induced spinal cord damage. We developed minimum and mean thresholds for damage from these pre-clinical studies. When these thresholds were plotted against the parameters used in recent pre-clinical ultrasonic spinal cord neuromodulation studies, the majority of the neuromodulation studies were near or above the minimum threshold. This suggests that a thermal neuromodulatory effect may exist for ultrasonic spinal cord neuromodulation, and that the thermal dose must be carefully controlled to avoid damage to the spinal cord. By contrast, the intensity-exposure duration threshold had no predictive value when applied to blood-spinal cord barrier opening studies that employed injected contrast agents. Most blood-spinal cord barrier opening studies observed slight to severe damage, except for small animal studies that employed an active feedback control method to limit pressures based on measured bubble oscillation behavior. The development of new focused ultrasound spinal cord applications perhaps reflects the recent success in the development of focused ultrasound brain applications, and recent work has begun on the translation of these technologies from brain to spinal cord. However, a great deal of work remains to be done, particularly with respect to developing and accepting safety standards for these applications.
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Affiliation(s)
- Rui Xu
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
| | - Bradley E Treeby
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Eleanor Martin
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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4
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Kofoed RH, Aubert I. Focused ultrasound gene delivery for the treatment of neurological disorders. Trends Mol Med 2024; 30:263-277. [PMID: 38216449 DOI: 10.1016/j.molmed.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 01/14/2024]
Abstract
The transformative potential of gene therapy has been demonstrated in humans. However, there is an unmet need for non-invasive targeted gene delivery and regulation in the treatment of brain disorders. Transcranial focused ultrasound (FUS) has gained tremendous momentum to address these challenges. FUS non-invasively modulates brain cells and their environment, and is a powerful tool to facilitate gene delivery across the blood-brain barrier (BBB) with millimeter precision and promptly regulate transgene expression. This review highlights technical aspects of FUS-mediated gene therapies for the central nervous system (CNS) and lessons learned from discoveries in other organs. Understanding the possibilities and remaining obstacles of FUS-mediated gene therapy will be necessary to harness remarkable technologies and create life-changing treatments for neurological disorders.
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Affiliation(s)
- Rikke Hahn Kofoed
- Department of Neurosurgery, Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 165, 8200 Aarhus N, Denmark; Center for Experimental Neuroscience (CENSE), Department of Neurosurgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 165, 8200 Aarhus N, Denmark; Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada.
| | - Isabelle Aubert
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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Wang YY, Cheng J, Liu YD, Wang YP, Yang QW, Zhou N. Exosome-based regenerative rehabilitation: A novel ice breaker for neurological disorders. Biomed Pharmacother 2023; 169:115920. [PMID: 37995565 DOI: 10.1016/j.biopha.2023.115920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/11/2023] [Accepted: 11/20/2023] [Indexed: 11/25/2023] Open
Abstract
Neurological disorders affect a large population, often leading to different levels of disability and resulting in decreased quality of life. Due to the limited recovery obtained from surgical procedures and other medical approaches, a large number of patients with prolonged dysfunction receive neurorehabilitation protocols to improve their neural plasticity and regeneration. However, the poor neural regeneration ability cannot effectively rebuild the tissue integrity and neural functional networks; consequently, the prognoses of neurorehabilitation remain undetermined. To increase the chances of neural regeneration and functional recovery for patients with neurological disorders, regenerative rehabilitation was introduced with combined regenerative medicine and neurorehabilitation protocols to repair neural tissue damage and create an optimized biophysical microenvironment for neural regeneration potential. With the deepening of exosome research, an increasing number of studies have found that the systemic therapeutic effects of neurorehabilitation approaches are mediated by exosomes released by physically stimulated cells, which provides new insight into rehabilitative mechanisms. Meanwhile, exosome therapy also serves as an alternative cell-free therapy of regenerative medicine that is applied in partnership with neurorehabilitation approaches and formulates exosome-based neurological regenerative rehabilitation. In this study, we review the current state of exosome-associated neurorehabilitation. On the one hand, we focus on presenting the varied mediating effects of exosomes in neurorehabilitation protocols of specific neurological pathologies; on the other hand, we discuss the diverse combinations of exosome therapies and neurorehabilitation approaches in the field of neurological regenerative rehabilitation, aiming to increase the awareness of exosome research and applications in the rehabilitation of neurological disorders.
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Affiliation(s)
- Yuan-Yi Wang
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Jin Cheng
- Department of Sport Medicine, Peking University Third Hospital, Beijing, China
| | - Ya-Dong Liu
- Department of Spine Surgery, The First Hospital of Jilin University, Changchun, Jilin Province, China
| | - Yi-Peng Wang
- Department of Orthopedics, Peking Union Medical College Hospital, Beijing, China.
| | - Qi-Wei Yang
- Medical Research Center, The Second Hospital of Jilin University, Changchun, Jilin Province, China.
| | - Nan Zhou
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Henan Province, China.
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Grewal S, Gonçalves de Andrade E, Kofoed RH, Matthews PM, Aubert I, Tremblay MÈ, Morse SV. Using focused ultrasound to modulate microglial structure and function. Front Cell Neurosci 2023; 17:1290628. [PMID: 38164436 PMCID: PMC10757935 DOI: 10.3389/fncel.2023.1290628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/31/2023] [Indexed: 01/03/2024] Open
Abstract
Transcranial focused ultrasound (FUS) has the unique ability to target regions of the brain with high spatial precision, in a minimally invasive manner. Neuromodulation studies have shown that FUS can excite or inhibit neuronal activity, demonstrating its tremendous potential to improve the outcome of neurological diseases. Recent evidence has also shed light on the emerging promise that FUS has, with and without the use of intravenously injected microbubbles, in modulating the blood-brain barrier and the immune cells of the brain. As the resident immune cells of the central nervous system, microglia are at the forefront of the brain's maintenance and immune defense. Notably, microglia are highly dynamic and continuously survey the brain parenchyma by extending and retracting their processes. This surveillance activity aids microglia in performing key physiological functions required for brain activity and plasticity. In response to stressors, microglia rapidly alter their cellular and molecular profile to help facilitate a return to homeostasis. While the underlying mechanisms by which both FUS and FUS + microbubbles modify microglial structure and function remain largely unknown, several studies in adult mice have reported changes in the expression of the microglia/macrophage marker ionized calcium binding adaptor molecule 1, and in their phagocytosis, notably of protein aggregates, such as amyloid beta. In this review, we discuss the demonstrated and putative biological effects of FUS and FUS + microbubbles in modulating microglial activities, with an emphasis on the key cellular and molecular changes observed in vitro and in vivo across models of brain health and disease. Understanding how this innovative technology can modulate microglia paves the way for future therapeutic strategies aimed to promote beneficial physiological microglial roles, and prevent or treat maladaptive responses.
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Affiliation(s)
- Sarina Grewal
- Department of Bioengineering, Imperial College London, London, United Kingdom
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Elisa Gonçalves de Andrade
- Neuroscience Graduate Program, Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Rikke Hahn Kofoed
- Department of Neurosurgery, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Center for Experimental Neuroscience-CENSE, Department of Neurosurgery, Aarhus University Hospital, Aarhus, Denmark
- Hurvitz Brain Sciences Research Program, Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Paul M. Matthews
- Department of Brain Sciences, Imperial College London, London, United Kingdom
- UK Dementia Research Institute, Imperial College London, London, United Kingdom
| | - Isabelle Aubert
- Hurvitz Brain Sciences Research Program, Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Axe Neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec, QC, Canada
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Sophie V. Morse
- Department of Bioengineering, Imperial College London, London, United Kingdom
- UK Dementia Research Institute, Imperial College London, London, United Kingdom
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7
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Odéen H, Hofstetter LW, Payne AH, Guiraud L, Dumont E, Parker DL. Simultaneous proton resonance frequency T 1 - MR shear wave elastography for MR-guided focused ultrasound multiparametric treatment monitoring. Magn Reson Med 2023; 89:2171-2185. [PMID: 36656135 PMCID: PMC10940047 DOI: 10.1002/mrm.29587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/21/2022] [Accepted: 12/30/2022] [Indexed: 01/20/2023]
Abstract
PURPOSE To develop an efficient MRI pulse sequence to simultaneously measure multiple parameters that have been shown to correlate with tissue nonviability following thermal therapies. METHODS A 3D segmented EPI pulse sequence was used to simultaneously measure proton resonance frequency shift (PRFS) MR thermometry (MRT), T1 relaxation time, and shear wave velocity induced by focused ultrasound (FUS) push pulses. Experiments were performed in tissue mimicking gelatin phantoms and ex vivo bovine liver. Using a carefully designed FUS triggering scheme, a heating duty cycle of approximately 65% was achieved by interleaving FUS ablation pulses with FUS push pulses to induce shear waves in the tissue. RESULTS In phantom studies, temperature increases measured with PRFS MRT and increases in T1 correlated with decreased shear wave velocity, consistent with material softening with increasing temperature. During ablation in ex vivo liver, temperature increase measured with PRFS MRT initially correlated with increasing T1 and decreasing shear wave velocity, and after tissue coagulation with decreasing T1 and increasing shear wave velocity. This is consistent with a previously described hysteresis in T1 versus PRFS curves and increased tissue stiffness with tissue coagulation. CONCLUSION An efficient approach for simultaneous and dynamic measurements of PRSF, T1 , and shear wave velocity during treatment is presented. This approach holds promise for providing co-registered dynamic measures of multiple parameters, which correlates to tissue nonviability during and following thermal therapies, such as FUS.
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Affiliation(s)
- Henrik Odéen
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Lorne W. Hofstetter
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Allison H. Payne
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA
| | | | | | - Dennis L. Parker
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA
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8
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Frizado AP, O'Reilly MA. A numerical investigation of passive acoustic mapping for monitoring bubble-mediated focused ultrasound treatment of the spinal cord. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:2271. [PMID: 37092915 DOI: 10.1121/10.0017836] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 03/28/2023] [Indexed: 05/03/2023]
Abstract
Focused ultrasound (FUS) combined with intravenous microbubbles (MBs) has been shown to increase drug delivery to the spinal cord in animal models. Eventual clinical translation of such a technique in the sensitive spinal cord requires robust treatment monitoring to ensure efficacy, localization, safety, and provide key intraprocedural feedback. Here, the use of passive acoustic mapping (PAM) of MB emissions with a spine-specific detector array in the context of transvertebral FUS sonications is investigated in silico. Using computed tomography-derived human vertebral geometry, transvertebral detection of MBs is evaluated over varying source locations with and without phase and amplitude corrections (PACs). The impact of prefocal cavitation is studied by simulating concurrent cavitation events in the canal and pre-laminar region. Spatially sensitive application of phase and amplitude is used to balance signal strengths emanating from different axial depths in combination with multiple dynamic ranges to elicit multisource viewing. Collectively, the results of this study encourage the use of PAM in transvertebral FUS applications with PACs to not only localize sources originating in the spinal canal but also multiple sources of innate amplitude mismatches when corrective methods are applied.
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Affiliation(s)
- Andrew Paul Frizado
- Department of Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
| | - Meaghan Anne O'Reilly
- Department of Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
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9
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Bhimreddy M, Routkevitch D, Hersh AM, Mohammadabadi A, Menta AK, Jiang K, Weber-Levine C, Davidar AD, Punnoose J, Kempski Leadingham KM, Doloff JC, Tyler B, Theodore N, Manbachi A. Disruption of the Blood-Spinal Cord Barrier using Low-Intensity Focused Ultrasound in a Rat Model. J Vis Exp 2023:10.3791/65113. [PMID: 36971451 PMCID: PMC10986840 DOI: 10.3791/65113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
Abstract
Low-intensity focused ultrasound (LIFU) uses ultrasonic pulsations at lower intensities than ultrasound and is being tested as a reversible and precise neuromodulatory technology. Although LIFU-mediated blood-brain barrier (BBB) opening has been explored in detail, no standardized technique for blood-spinal cord barrier (BSCB) opening has been established to date. Therefore, this protocol presents a method for successful BSCB disruption using LIFU sonication in a rat model, including descriptions of animal preparation, microbubble administration, target selection and localization, as well as BSCB disruption visualization and confirmation. The approach reported here is particularly useful for researchers who need a fast and cost-effective method to test and confirm target localization and precise BSCB disruption in a small animal model with a focused ultrasound transducer, evaluate the BSCB efficacy of sonication parameters, or explore applications for LIFU at the spinal cord, such as drug delivery, immunomodulation, and neuromodulation. Optimizing this protocol for individual use is recommended, especially for advancing future preclinical, clinical, and translational work.
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Affiliation(s)
- Meghana Bhimreddy
- Department of Neurosurgery, Johns Hopkins University School of Medicine
| | - Denis Routkevitch
- Department of Neurosurgery, Johns Hopkins University School of Medicine; Department of Biomedical Engineering, Johns Hopkins University; HEPIUS Innovation Laboratory, Johns Hopkins University School of Medicine
| | - Andrew M Hersh
- Department of Neurosurgery, Johns Hopkins University School of Medicine
| | - Ali Mohammadabadi
- Department of Neurosurgery, Johns Hopkins University School of Medicine; HEPIUS Innovation Laboratory, Johns Hopkins University School of Medicine
| | - Arjun K Menta
- Department of Neurosurgery, Johns Hopkins University School of Medicine
| | - Kelly Jiang
- Department of Neurosurgery, Johns Hopkins University School of Medicine
| | | | - A Daniel Davidar
- Department of Neurosurgery, Johns Hopkins University School of Medicine
| | - Joshua Punnoose
- Department of Neurosurgery, Johns Hopkins University School of Medicine; Department of Biomedical Engineering, Johns Hopkins University; HEPIUS Innovation Laboratory, Johns Hopkins University School of Medicine
| | - Kelley M Kempski Leadingham
- Department of Neurosurgery, Johns Hopkins University School of Medicine; HEPIUS Innovation Laboratory, Johns Hopkins University School of Medicine
| | - Joshua C Doloff
- Department of Biomedical Engineering, Johns Hopkins University
| | - Betty Tyler
- Department of Neurosurgery, Johns Hopkins University School of Medicine
| | - Nicholas Theodore
- Department of Neurosurgery, Johns Hopkins University School of Medicine; HEPIUS Innovation Laboratory, Johns Hopkins University School of Medicine
| | - Amir Manbachi
- Department of Neurosurgery, Johns Hopkins University School of Medicine; Department of Biomedical Engineering, Johns Hopkins University; HEPIUS Innovation Laboratory, Johns Hopkins University School of Medicine; Department of Electrical Engineering and Computer Science, Johns Hopkins University; Department of Mechanical Engineering, Johns Hopkins University; Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University;
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Kofoed RH, Dibia CL, Noseworthy K, Xhima K, Vacaresse N, Hynynen K, Aubert I. Efficacy of gene delivery to the brain using AAV and ultrasound depends on serotypes and brain areas. J Control Release 2022; 351:667-680. [DOI: 10.1016/j.jconrel.2022.09.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/18/2022] [Accepted: 09/23/2022] [Indexed: 02/01/2023]
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11
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Xu R, O'Reilly MA. Establishing density-dependent longitudinal sound speed in the vertebral lamina. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2022; 151:1516. [PMID: 35364923 DOI: 10.1121/10.0009316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 12/26/2021] [Indexed: 06/14/2023]
Abstract
Focused ultrasound treatments of the spinal cord may be facilitated using a phased array transducer and beamforming to correct spine-induced focal aberrations. Simulations can non-invasively calculate aberration corrections using x-ray computed tomography (CT) data that are correlated to density (ρ) and longitudinal sound speed (cL). We aimed to optimize vertebral lamina-specific cL(ρ) functions at a physiological temperature (37 °C) to maximize time domain simulation accuracy. Odd-numbered ex vivo human thoracic vertebrae were imaged with a clinical CT-scanner (0.511 × 0.511 × 0.5 mm), then sonicated with a transducer (514 kHz) focused on the canal via the vertebral lamina. Vertebra-induced signal time shifts were extracted from pressure waveforms recorded within the canals. Measurements were repeated 5× per vertebra, with 2.5 mm vertical vertebra shifts between measurements. Linear functions relating cL with CT-derived density were optimized. The optimized function was cL(ρ)=0.35(ρ-ρw)+ cL,w m/s, where w denotes water, giving the tested laminae a mean bulk density of 1600 ± 30 kg/m3 and a mean bulk cL of 1670 ± 60 m/s. The optimized lamina cL(ρ) function was accurate to λ/16 when implemented in a multi-layered ray acoustics model. This modelling accuracy will improve trans-spine ultrasound beamforming.
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Affiliation(s)
- Rui Xu
- Department of Medical Biophysics, University of Toronto, 101 College Street, Suite 15-701, Toronto, Ontario, M5G 1L7, Canada
| | - Meaghan A O'Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5, Canada
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Librizzi L, Uva L, Raspagliesi L, Gionso M, Regondi MC, Durando G, DiMeco F, de Curtis M, Prada F. Ultrasounds induce blood–brain barrier opening across a sonolucent polyolefin plate in an in vitro isolated brain preparation. Sci Rep 2022; 12:2906. [PMID: 35190597 PMCID: PMC8861168 DOI: 10.1038/s41598-022-06791-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/04/2022] [Indexed: 11/28/2022] Open
Abstract
The blood–brain barrier (BBB) represents a major obstacle to the delivery of drugs to the central nervous system. The combined use of low-intensity pulsed ultrasound waves and intravascular microbubbles (MB) represents a promising solution to this issue, allowing reversible disruption of the barrier. In this study, we evaluate the feasibility of BBB opening through a biocompatible, polyolefin-based plate in an in vitro whole brain model. Twelve in vitro guinea pig brains were employed; brains were insonated using a planar transducer with or without interposing the polyolefin plate during arterial infusion of MB. Circulating MBs were visualized with an ultrasonographic device with a linear probe. BBB permeabilization was assessed by quantifying at confocal microscopy the extravasation of FITC-albumin perfused after each treatment. US-treated brains displayed BBB permeabilization exclusively in the volume under the US beam; no significant differences were observed between brains insonated with or without the polyolefin plate. Control brains not perfused with MB did not show signs of FITC-albumin extravasation. Our preclinical study suggests that polyolefin cranial plate could be implanted as a skull replacement to maintain craniotomic windows and perform post-surgical repeated BBB opening with ultrasound guidance to deliver therapeutic agents to the central nervous system.
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13
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Kofoed RH, Heinen S, Silburt J, Dubey S, Dibia CL, Maes M, Simpson EM, Hynynen K, Aubert I. Transgene distribution and immune response after ultrasound delivery of rAAV9 and PHP.B to the brain in a mouse model of amyloidosis. Mol Ther Methods Clin Dev 2021; 23:390-405. [PMID: 34761053 PMCID: PMC8560718 DOI: 10.1016/j.omtm.2021.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 08/12/2021] [Accepted: 10/05/2021] [Indexed: 01/01/2023]
Abstract
Efficient disease-modifying treatments for Alzheimer disease, the most common form of dementia, have yet to be established. Gene therapy has the potential to provide the long-term production of therapeutic in the brain following a single administration. However, the blood-brain barrier poses a challenge for gene delivery to the adult brain. We investigated the transduction efficiency and immunological response following non-invasive gene-delivery strategies to the brain of a mouse model of amyloidosis. Two emerging technologies enabling gene delivery across the blood-brain barrier were used to establish the minimal vector dosage required to reach the brain: (1) focused ultrasound combined with intravenous microbubbles, which increases the permeability of the blood-brain barrier at targeted sites and (2) the recombinant adeno-associated virus (rAAV)-based capsid named rAAV-PHP.B. We found that equal intravenous dosages of rAAV9 combined with focused ultrasound, or rAAV-PHP.B, were required for brain gene delivery. In contrast to rAAV9, focused ultrasound did not decrease the rAAV-PHP.B dosage required to transduce brain cells in a mouse model of amyloidosis. The non-invasive rAAV delivery to the brain using rAAV-PHP.B or rAAV9 with focused ultrasound triggered an immune reaction including major histocompatibility complex class II expression, complement system and microglial activation, and T cell infiltration.
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Affiliation(s)
- Rikke Hahn Kofoed
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Stefan Heinen
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Joseph Silburt
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Sonam Dubey
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Chinaza Lilian Dibia
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Miriam Maes
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Elizabeth M. Simpson
- Centre for Molecular Medicine and Therapeutics at British Columbia Children’s Hospital, Department of Medical Genetics, The University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Kullervo Hynynen
- Physical Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Medical Biophysics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Isabelle Aubert
- Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
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14
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Zhang M, Rodrigues A, Zhou Q, Li G. Focused ultrasound: growth potential and future directions in neurosurgery. J Neurooncol 2021; 156:23-32. [PMID: 34410576 DOI: 10.1007/s11060-021-03820-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/31/2021] [Indexed: 12/18/2022]
Abstract
Over the past two decades, vast improvements in focused ultrasound (FUS) technology have made the therapy an exciting addition to the neurosurgical armamentarium. In this time period, FUS has gained US Food and Drug Administration (FDA) approval for the treatment of two neurological disorders, and ongoing efforts seek to expand the lesion profile that is amenable to ultrasonic intervention. In the following review, we highlight future applications for FUS therapy and compare its potential role against established technologies, including deep brain stimulation and stereotactic radiosurgery. Particular attention is paid to tissue ablation, blood-brain-barrier opening, and gene therapy. We also address technical and infrastructural challenges involved with FUS use and summarize the hurdles that must be overcome before FUS becomes widely accepted in the neurosurgical community.
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Affiliation(s)
- Michael Zhang
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA. .,Center for Academic Medicine, Neurosurgery, Stanford University School of Medicine, MC 5327, 453 Quarry Road, Palo Alto, CA, 94304, USA.
| | - Adrian Rodrigues
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Quan Zhou
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.,Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Gordon Li
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
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15
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Chen KT, Wei KC, Liu HL. Focused Ultrasound Combined with Microbubbles in Central Nervous System Applications. Pharmaceutics 2021; 13:pharmaceutics13071084. [PMID: 34371774 PMCID: PMC8308978 DOI: 10.3390/pharmaceutics13071084] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 12/20/2022] Open
Abstract
The blood–brain barrier (BBB) protects the central nervous system (CNS) from invasive pathogens and maintains the homeostasis of the brain. Penetrating the BBB has been a major challenge in the delivery of therapeutic agents for treating CNS diseases. Through a physical acoustic cavitation effect, focused ultrasound (FUS) combined with microbubbles achieves the local detachment of tight junctions of capillary endothelial cells without inducing neuronal damage. The bioavailability of therapeutic agents is increased only in the area targeted by FUS energy. FUS with circulating microbubbles is currently the only method for inducing precise, transient, reversible, and noninvasive BBB opening (BBBO). Over the past decade, FUS-induced BBBO (FUS-BBBO) has been preclinically confirmed to not only enhance the penetration of therapeutic agents in the CNS, but also modulate focal immunity and neuronal activity. Several recent clinical human trials have demonstrated both the feasibility and potential advantages of using FUS-BBBO in diseased patients. The promising results support adding FUS-BBBO as a multimodal therapeutic strategy in modern CNS disease management. This review article explores this technology by describing its physical mechanisms and the preclinical findings, including biological effects, therapeutic concepts, and translational design of human medical devices, and summarizes completed and ongoing clinical trials.
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Affiliation(s)
- Ko-Ting Chen
- Department of Neurosurgery, Linkou Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan;
- Ph.D. Program in Biomedical Engineering, Chang Gung University, Guishan, Taoyuan 333, Taiwan
- Neuroscience Research Center, Linkou Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan
| | - Kuo-Chen Wei
- Department of Neurosurgery, Linkou Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan;
- Neuroscience Research Center, Linkou Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan
- Department of Neurosurgery, New Taipei Municipal TuCheng Hospital, Chang Gung Medical Foundation, TuCheng, New Taipei 236, Taiwan
- School of Medicine, Chang Gung University, Guishan, Taoyuan 333, Taiwan
- Correspondence: (K.-C.W.); (H.-L.L.)
| | - Hao-Li Liu
- Department of Electrical Engineering, National Taiwan University, Da’an, Taipei 106, Taiwan
- Department of Biomedical Engineering, National Taiwan University, Da’an, Taipei 106, Taiwan
- Correspondence: (K.-C.W.); (H.-L.L.)
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16
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Cross CG, Payne AH, Hawryluk GW, Haag-Roeger R, Cheeniyil R, Brady D, Odéen H, Minoshima S, Cross DJ, Anzai Y. Technical Note: Quantification of blood-spinal cord barrier permeability after application of magnetic resonance-guided focused ultrasound in spinal cord injury. Med Phys 2021; 48:4395-4401. [PMID: 33999427 DOI: 10.1002/mp.14947] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 01/03/2023] Open
Abstract
PURPOSE To demonstrate that magnetic resonance-guided focused ultrasound (MRgFUS) facilitates blood-spinal cord barrier (BSCB) permeability and develop observer-independent MRI quantification of BSCB permeability after MRgFUS for spinal cord injury (SCI). METHODS Noninjured Sprague-Dawley rats (n = 3) underwent MRgFUS and were administered Evans blue post-MRgFUS to confirm BSCB opening. Absorbance was measured by spectrophotometry and correlated with its corresponding image intensity. Rats (n = 21) underwent T8-T10 laminectomy and extradural compression of the spinal cord (23g weighted aneurysm-type clip, 1 min). The intervention group (n = 11) was placed on a preclinical MRgFUS system, administered microbubbles (Optison, 0.2 mL/kg), and received 3 MRgFUS sonications (25 ms bursts, 1 Hz pulses for 3 min, 3 acoustic W, approximately 1.0-2.1 MPa peak pressure as measured via hydrophone). The sham group (n = 10) received equivalent procedures with no sonications. T1w MRI was obtained both pre- and post-MRgFUS BSCB opening. Spinal cords were segmented manually or semiautomatically and a Pearson correlation with P ≤ 0.001 was used to correlate the two segmentation methods. MRgFUS sonication and control regions intensity values were evaluated with a paired t-test with a P ≤ 0.01. RESULTS Semiautomatic segmentation reduced computational time by 95% and was correlated with manual segmentation (Pearson = 0.92, P < 0.001, n = 71 regions). In the noninjured rat group, Evans blue absorbance correlated with image intensity in the MRgFUS and control regions (Pearson = 0.82, P = 0.02, n = 6). In rats that underwent the SCI procedure, an increase in signal intensity in the MRgFUS targeted region relative to control was seen in all SCI rats (10.65 ± 12.4%, range: 0.96-43.9%, n = 11, P = 0.002). SCI sham MRgFUS revealed no change (0.63 ± 0.52%, 95% CI 0.320.95, n = 10). This result was significant between both groups (P = 0.003). CONCLUSION The implemented semiautomatic segmentation procedure improved data analysis efficiency. Quantitative methods using contrast-enhanced MRI with histological validation are sensitive for detection of blood-spinal cord barrier opening induced by magnetic resonance-guided focused ultrasound.
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Affiliation(s)
- Chloe G Cross
- School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Allison H Payne
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | | | - Riley Haag-Roeger
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Rahul Cheeniyil
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Dalton Brady
- School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Henrik Odéen
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Satoshi Minoshima
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Donna J Cross
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Yoshimi Anzai
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
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17
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Vasan L, Park E, David LA, Fleming T, Schuurmans C. Direct Neuronal Reprogramming: Bridging the Gap Between Basic Science and Clinical Application. Front Cell Dev Biol 2021; 9:681087. [PMID: 34291049 PMCID: PMC8287587 DOI: 10.3389/fcell.2021.681087] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/02/2021] [Indexed: 12/15/2022] Open
Abstract
Direct neuronal reprogramming is an innovative new technology that involves the conversion of somatic cells to induced neurons (iNs) without passing through a pluripotent state. The capacity to make new neurons in the brain, which previously was not achievable, has created great excitement in the field as it has opened the door for the potential treatment of incurable neurodegenerative diseases and brain injuries such as stroke. These neurological disorders are associated with frank neuronal loss, and as new neurons are not made in most of the adult brain, treatment options are limited. Developmental biologists have paved the way for the field of direct neuronal reprogramming by identifying both intrinsic cues, primarily transcription factors (TFs) and miRNAs, and extrinsic cues, including growth factors and other signaling molecules, that induce neurogenesis and specify neuronal subtype identities in the embryonic brain. The striking observation that postmitotic, terminally differentiated somatic cells can be converted to iNs by mis-expression of TFs or miRNAs involved in neural lineage development, and/or by exposure to growth factors or small molecule cocktails that recapitulate the signaling environment of the developing brain, has opened the door to the rapid expansion of new neuronal reprogramming methodologies. Furthermore, the more recent applications of neuronal lineage conversion strategies that target resident glial cells in situ has expanded the clinical potential of direct neuronal reprogramming techniques. Herein, we present an overview of the history, accomplishments, and therapeutic potential of direct neuronal reprogramming as revealed over the last two decades.
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Affiliation(s)
- Lakshmy Vasan
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Eunjee Park
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Luke Ajay David
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Taylor Fleming
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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18
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Fletcher SMP, Choi M, Ramesh R, O'Reilly MA. Focused Ultrasound-Induced Blood-Spinal Cord Barrier Opening Using Short-Burst Phase-Keying Exposures in Rats: A Parameter Study. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:1747-1760. [PMID: 33879388 DOI: 10.1016/j.ultrasmedbio.2021.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/05/2021] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Transient opening of the blood-spinal cord barrier has the potential to improve drug delivery options to the spinal cord. We previously developed short-burst phase-keying exposures to reduce focal depth of field and mitigate standing waves in the spinal canal. However, optimal short-burst phase-keying parameters for drug delivery have not been identified. Here, the effects of pressure, treatment duration, pulse length, burst repetition frequency and burst length on resulting tissue effects were investigated. Increased in situ pressures (0.23-0.33 MPa) led to increased post-treatment T1-weighted contrast enhancement in magnetic resonance imaging (p = 0.015). Increased treatment duration (120 vs. 300 s) led to increased enhancement, but without statistical significance (p = 0.056). Increased burst repetition frequency (20 vs. 40 kHz) yielded a non-significant increase in enhancement (p = 0.064) but corresponded with increased damage observed on histology. No difference was observed in enhancement between pulse lengths of 2 and 10 ms (p = 0.912), corresponding with a sharp drop in the recorded second harmonic signal during the first 2 ms of the pulse. Increasing the burst length from two to five cycles (514 kHz) led to increased enhancement (p = 0.014). Results indicate that increasing the burst length may be the most effective method to enhance drug delivery. Additionally, shorter pulse lengths may allow more interleaved targets, and therefore a larger treatment volume, within one sonication.
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Affiliation(s)
- Stecia-Marie P Fletcher
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
| | - Min Choi
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Ranjith Ramesh
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Meaghan A O'Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
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19
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Hwang BY, Mampre D, Ahmed AK, Suk I, Anderson WS, Manbachi A, Theodore N. Ultrasound in Traumatic Spinal Cord Injury: A Wide-Open Field. Neurosurgery 2021; 89:372-382. [PMID: 34098572 DOI: 10.1093/neuros/nyab177] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/19/2021] [Indexed: 02/02/2023] Open
Abstract
Traumatic spinal cord injury (SCI) is a common and devastating condition. In the absence of effective validated therapies, there is an urgent need for novel methods to achieve injury stabilization, regeneration, and functional restoration in SCI patients. Ultrasound is a versatile platform technology that can provide a foundation for viable diagnostic and therapeutic interventions in SCI. In particular, real-time perfusion and inflammatory biomarker monitoring, focal pharmaceutical delivery, and neuromodulation are capabilities that can be harnessed to advance our knowledge of SCI pathophysiology and to develop novel management and treatment options. Our review suggests that studies that evaluate the benefits and risks of ultrasound in SCI are severely lacking and our understanding of the technology's potential impact remains poorly understood. Although the complex anatomy and physiology of the spine and the spinal cord remain significant challenges, continued technological advances will help the field overcome the current barriers and bring ultrasound to the forefront of SCI research and development.
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Affiliation(s)
- Brian Y Hwang
- Division of Functional Neurosurgery, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - David Mampre
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - A Karim Ahmed
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ian Suk
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - William S Anderson
- Division of Functional Neurosurgery, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Amir Manbachi
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Nicholas Theodore
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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20
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McMahon D, O'Reilly MA, Hynynen K. Therapeutic Agent Delivery Across the Blood-Brain Barrier Using Focused Ultrasound. Annu Rev Biomed Eng 2021; 23:89-113. [PMID: 33752471 DOI: 10.1146/annurev-bioeng-062117-121238] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Specialized features of vasculature in the central nervous system greatly limit therapeutic treatment options for many neuropathologies. Focused ultrasound, in combination with circulating microbubbles, can be used to transiently and noninvasively increase cerebrovascular permeability with a high level of spatial precision. For minutes to hours following sonication, drugs can be administered systemically to extravasate in the targeted brain regions and exert a therapeutic effect, after which permeability returns to baseline levels. With the wide range of therapeutic agents that can be delivered using this approach and the growing clinical need, focused ultrasound and microbubble (FUS+MB) exposure in the brain has entered human testing to assess safety. This review outlines the use of FUS+MB-mediated cerebrovascular permeability enhancement as a drug delivery technique, details several technical and biological considerations of this approach, summarizes results from the clinical trials conducted to date, and discusses the future direction of the field.
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Affiliation(s)
- Dallan McMahon
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada; .,Department of Medical Biophysics, University of Toronto, Toronto, Ontario M4N 3M5, Canada
| | - Meaghan A O'Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada; .,Department of Medical Biophysics, University of Toronto, Toronto, Ontario M4N 3M5, Canada
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada; .,Department of Medical Biophysics, University of Toronto, Toronto, Ontario M4N 3M5, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M4N 3M5, Canada
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21
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Characterization of ultrasound-mediated delivery of trastuzumab to normal and pathologic spinal cord tissue. Sci Rep 2021; 11:4412. [PMID: 33627726 PMCID: PMC7904756 DOI: 10.1038/s41598-021-83874-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 02/08/2021] [Indexed: 01/31/2023] Open
Abstract
Extensive studies on focused ultrasound (FUS)-mediated drug delivery through the blood-brain barrier have been published, yet little work has been published on FUS-mediated drug delivery through the blood-spinal cord barrier (BSCB). This work aims to quantify the delivery of the monoclonal antibody trastuzumab to rat spinal cord tissue and characterize its distribution within a model of leptomeningeal metastases. 10 healthy Sprague-Dawley rats were treated with FUS + trastuzumab and sacrificed at 2-h or 24-h post-FUS. A human IgG ELISA (Abcam) was used to measure trastuzumab concentration and a 12 ± fivefold increase was seen in treated tissue over control tissue at 2 h versus no increase at 24 h. Three athymic nude rats were inoculated with MDA-MB-231-H2N HER2 + breast cancer cells between the meninges in the thoracic region of the spinal cord and treated with FUS + trastuzumab. Immunohistochemistry was performed to visualize trastuzumab delivery, and semi-quantitative analysis revealed similar or more intense staining in tumor tissue compared to healthy tissue suggesting a comparable or greater concentration of trastuzumab was achieved. FUS can increase the permeability of the BSCB, improving drug delivery to specifically targeted regions of healthy and pathologic tissue in the spinal cord. The achieved concentrations within the healthy tissue are comparable to those reported in the brain.
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22
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Weber-Adrian D, Kofoed RH, Silburt J, Noroozian Z, Shah K, Burgess A, Rideout S, Kügler S, Hynynen K, Aubert I. Systemic AAV6-synapsin-GFP administration results in lower liver biodistribution, compared to AAV1&2 and AAV9, with neuronal expression following ultrasound-mediated brain delivery. Sci Rep 2021; 11:1934. [PMID: 33479314 PMCID: PMC7820310 DOI: 10.1038/s41598-021-81046-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/20/2020] [Indexed: 02/06/2023] Open
Abstract
Non-surgical gene delivery to the brain can be achieved following intravenous injection of viral vectors coupled with transcranial MRI-guided focused ultrasound (MRIgFUS) to temporarily and locally permeabilize the blood-brain barrier. Vector and promoter selection can provide neuronal expression in the brain, while limiting biodistribution and expression in peripheral organs. To date, the biodistribution of adeno-associated viruses (AAVs) within peripheral organs had not been quantified following intravenous injection and MRIgFUS delivery to the brain. We evaluated the quantity of viral DNA from the serotypes AAV9, AAV6, and a mosaic AAV1&2, expressing green fluorescent protein (GFP) under the neuron-specific synapsin promoter (syn). AAVs were administered intravenously during MRIgFUS targeting to the striatum and hippocampus in mice. The syn promoter led to undetectable levels of GFP expression in peripheral organs. In the liver, the biodistribution of AAV9 and AAV1&2 was 12.9- and 4.4-fold higher, respectively, compared to AAV6. The percentage of GFP-positive neurons in the FUS-targeted areas of the brain was comparable for AAV6-syn-GFP and AAV1&2-syn-GFP. In summary, MRIgFUS-mediated gene delivery with AAV6-syn-GFP had lower off-target biodistribution in the liver compared to AAV9 and AAV1&2, while providing neuronal GFP expression in the striatum and hippocampus.
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Affiliation(s)
- Danielle Weber-Adrian
- grid.410356.50000 0004 1936 8331Present Address: Faculty of Health Sciences, School of Medicine, Queen′s University, Kingston, ON Canada ,grid.17063.330000 0001 2157 2938Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Rikke Hahn Kofoed
- grid.17063.330000 0001 2157 2938Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Joseph Silburt
- grid.17063.330000 0001 2157 2938Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Zeinab Noroozian
- grid.17063.330000 0001 2157 2938Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Kairavi Shah
- grid.17063.330000 0001 2157 2938Institute of Medical Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Alison Burgess
- grid.17063.330000 0001 2157 2938Physical Sciences, Sunnybrook Research Institute, Toronto, ON Canada
| | - Shawna Rideout
- grid.17063.330000 0001 2157 2938Physical Sciences, Sunnybrook Research Institute, Toronto, ON Canada
| | - Sebastian Kügler
- grid.411984.10000 0001 0482 5331Department of Neurology, Center Nanoscale Microscopy and Physiology of the Brain (CNMPB) at University Medical Center Göttingen, Göttingen, Germany
| | - Kullervo Hynynen
- grid.17063.330000 0001 2157 2938Physical Sciences, Sunnybrook Research Institute, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Medical Biophysics, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
| | - Isabelle Aubert
- grid.17063.330000 0001 2157 2938Biological Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON Canada
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23
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Jacobs AH, Schelhaas S, Viel T, Waerzeggers Y, Winkeler A, Zinnhardt B, Gelovani J. Imaging of Gene and Cell-Based Therapies: Basis and Clinical Trials. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00060-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Liu D, Zhu M, Zhang Y, Diao Y. Crossing the blood-brain barrier with AAV vectors. Metab Brain Dis 2021; 36:45-52. [PMID: 33201426 DOI: 10.1007/s11011-020-00630-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/12/2020] [Indexed: 12/26/2022]
Abstract
Central nervous system (CNS) diseases are some of the most difficult to treat because the blood-brain barrier (BBB) almost entirely limits the passage of many therapeutic drugs into the CNS. Gene therapy based on the adeno-associated virus (AAV) vector has the potential to overcome this problem. For example, an AAV serotype AAV9 has been widely studied for its ability to cross the BBB to transduce astrocytes, but its efficiency is limited. The emergence of AAV directed evolution technology provides a solution, and the variants derived from AAV9 directed evolution have been shown to have significantly higher crossing efficiency than AAV9. However, the mechanisms by which AAV crosses the BBB are still unclear. In this review, we focus on recent advances in crossing the blood-brain barrier with AAV vectors. We first review the AAV serotypes that can be applied to treating CNS diseases. Recent progress in possible AAV crossing the BBB and transduction mechanisms are then summarized. Finally, the methods to improve the AAV transduction efficiency are discussed.
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Affiliation(s)
- Dan Liu
- School of Biomedical Sciences, College of Chemical Engineering, Huaqiao University, Xiamen, Fujian, China.
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China.
| | - Mingyang Zhu
- School of Biomedical Sciences, College of Chemical Engineering, Huaqiao University, Xiamen, Fujian, China
| | - Yuqian Zhang
- School of Biomedical Sciences, College of Chemical Engineering, Huaqiao University, Xiamen, Fujian, China
| | - Yong Diao
- School of Biomedical Sciences, College of Chemical Engineering, Huaqiao University, Xiamen, Fujian, China
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25
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Todd N, McDannold N, Borsook D. Targeted manipulation of pain neural networks: The potential of focused ultrasound for treatment of chronic pain. Neurosci Biobehav Rev 2020; 115:238-250. [PMID: 32534900 PMCID: PMC7483565 DOI: 10.1016/j.neubiorev.2020.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 04/24/2020] [Accepted: 06/04/2020] [Indexed: 12/29/2022]
Abstract
Focused ultrasound (FUS) is a promising technology for facilitating treatment of brain diseases including chronic pain. Focused ultrasound is a unique modality for delivering therapeutic levels of energy into the body, including the central nervous system (CNS). It is non-invasive and can target spatially localized effects through the intact skull to cortical or subcortical regions of the brain. FUS can achieve three different mechanisms of action in the brain that are relevant for chronic pain treatment: (1) localized thermal ablation of neural tissue; (2) localized and transient disruption of the blood-brain barrier for targeted drug delivery to CNS structures; and (3) inhibition or stimulation of neuronal activity in targeted regions. This review provides an in-depth look at the technology of FUS with emphasis placed on applications to CNS-based treatments of chronic pain. While still in the early stages of clinical translation and with some technical challenges remaining, we suggest that FUS has great potential as a novel approach for manipulating CNS networks involved in pain treatment.
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Affiliation(s)
- Nick Todd
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; Center for Pain and the Brain, 1 Autumn Street, Boston Children's Hospital, Boston, MA, 02115, United States.
| | - Nathan McDannold
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - David Borsook
- Center for Pain and the Brain, 1 Autumn Street, Boston Children's Hospital, Boston, MA, 02115, United States; Department of Anesthesia, Perioperative, and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, United States
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26
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Fletcher SMP, Choi M, Ogrodnik N, O'Reilly MA. A Porcine Model of Transvertebral Ultrasound and Microbubble-Mediated Blood-Spinal Cord Barrier Opening. Am J Cancer Res 2020; 10:7758-7774. [PMID: 32685018 PMCID: PMC7359082 DOI: 10.7150/thno.46821] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/05/2020] [Indexed: 12/17/2022] Open
Abstract
Blood-spinal cord barrier opening, using focused ultrasound and microbubbles, has the potential to improve drug delivery for the treatment of spinal cord pathologies. Delivering and detecting ultrasound through the spine is a challenge for clinical translation. We have previously developed short burst, phase keying exposures, which can be used in a dual-aperture configuration to address clinical scale targeting challenges. Here we demonstrate the use of these pulses for blood-spinal cord barrier opening, in vivo in pigs. Methods: The spinal cords of Yorkshire pigs (n=8) were targeted through the vertebral laminae, in the lower thoracic to upper lumbar region using focused ultrasound (486 kHz) and microbubbles. Four animals were treated with a combination of pulsed sinusoidal exposures (1.0-4.0 MPa, non-derated) and pulsed short burst, phase keying exposures (1.0-2.0 MPa, non-derated). Four animals were treated using ramped short burst, phase keying exposures (1.8-2.1 MPa, non-derated). A 250 kHz narrowband receiver was used to detect acoustic emissions from microbubbles. Blood-spinal cord barrier opening was assessed by the extravasation of Evans blue dye. Histological analysis of the spinal cords was used to assess tissue damage and excised vertebral samples were used in benchtop experiments. Results: Ramped short burst, phase keying exposures successfully modified the blood-spinal cord barrier at 16/24 targeted locations, as assessed by the extravasation of Evans blue dye. At 4 of these locations, opening was confirmed with minimal adverse effects observed through histology. Transmission measurements through excised vertebrae indicated a mean transmission of (47.0 ± 7.0 %) to the target. Conclusions: This study presents the first evidence of focused ultrasound-induced blood-spinal cord barrier opening in a large animal model, through the intact spine. This represents an important step towards clinical translation.
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27
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Kooiman K, Roovers S, Langeveld SAG, Kleven RT, Dewitte H, O'Reilly MA, Escoffre JM, Bouakaz A, Verweij MD, Hynynen K, Lentacker I, Stride E, Holland CK. Ultrasound-Responsive Cavitation Nuclei for Therapy and Drug Delivery. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:1296-1325. [PMID: 32165014 PMCID: PMC7189181 DOI: 10.1016/j.ultrasmedbio.2020.01.002] [Citation(s) in RCA: 159] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/20/2019] [Accepted: 01/07/2020] [Indexed: 05/03/2023]
Abstract
Therapeutic ultrasound strategies that harness the mechanical activity of cavitation nuclei for beneficial tissue bio-effects are actively under development. The mechanical oscillations of circulating microbubbles, the most widely investigated cavitation nuclei, which may also encapsulate or shield a therapeutic agent in the bloodstream, trigger and promote localized uptake. Oscillating microbubbles can create stresses either on nearby tissue or in surrounding fluid to enhance drug penetration and efficacy in the brain, spinal cord, vasculature, immune system, biofilm or tumors. This review summarizes recent investigations that have elucidated interactions of ultrasound and cavitation nuclei with cells, the treatment of tumors, immunotherapy, the blood-brain and blood-spinal cord barriers, sonothrombolysis, cardiovascular drug delivery and sonobactericide. In particular, an overview of salient ultrasound features, drug delivery vehicles, therapeutic transport routes and pre-clinical and clinical studies is provided. Successful implementation of ultrasound and cavitation nuclei-mediated drug delivery has the potential to change the way drugs are administered systemically, resulting in more effective therapeutics and less-invasive treatments.
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Affiliation(s)
- Klazina Kooiman
- Department of Biomedical Engineering, Thoraxcenter, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands.
| | - Silke Roovers
- Ghent Research Group on Nanomedicines, Lab for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Simone A G Langeveld
- Department of Biomedical Engineering, Thoraxcenter, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Robert T Kleven
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Heleen Dewitte
- Ghent Research Group on Nanomedicines, Lab for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, Ghent, Belgium; Laboratory for Molecular and Cellular Therapy, Medical School of the Vrije Universiteit Brussel, Jette, Belgium; Cancer Research Institute Ghent (CRIG), Ghent University Hospital, Ghent University, Ghent, Belgium
| | - Meaghan A O'Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | | | - Ayache Bouakaz
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Martin D Verweij
- Department of Biomedical Engineering, Thoraxcenter, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands; Laboratory of Acoustical Wavefield Imaging, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Ine Lentacker
- Ghent Research Group on Nanomedicines, Lab for General Biochemistry and Physical Pharmacy, Department of Pharmaceutical Sciences, Ghent University, Ghent, Belgium; Cancer Research Institute Ghent (CRIG), Ghent University Hospital, Ghent University, Ghent, Belgium
| | - Eleanor Stride
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Christy K Holland
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, USA; Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH, USA
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28
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Xu R, O'Reilly MA. A Spine-Specific Phased Array for Transvertebral Ultrasound Therapy: Design and Simulation. IEEE Trans Biomed Eng 2020; 67:256-267. [DOI: 10.1109/tbme.2019.2912146] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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29
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Yao X, Adams MS, Jones PD, Diederich CJ, Verkman AS. Noninvasive, Targeted Creation of Neuromyelitis Optica Pathology in AQP4-IgG Seropositive Rats by Pulsed Focused Ultrasound. J Neuropathol Exp Neurol 2019; 78:47-56. [PMID: 30500945 DOI: 10.1093/jnen/nly107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Neuromyelitis optica spectrum disorders (herein called NMO) is an autoimmune disease of the CNS characterized by astrocyte injury, inflammation, and demyelination. In seropositive NMO, immunoglobulin G autoantibodies against aquaporin-4 (AQP4-IgG) cause primary astrocyte injury. A passive transfer model of NMO was developed in which spatially targeted access of AQP4-IgG into the CNS of seropositive rats was accomplished by pulsed focused ultrasound through intact skin. Following intravenous administration of microbubbles, pulsed ultrasound at 0.5 MPa peak acoustic pressure was applied using a 1 MHz transducer with 6-cm focal length. In brain, the transient opening of the blood-brain barrier (BBB) in an approximately prolate ellipsoidal volume of diameter ∼3.5 mm and length ∼44 mm allowed entry of IgG-size molecules for up to 3-6 hours. The ultrasound treatment did not cause erythrocyte extravasation or inflammation. Ultrasound treatment in AQP4-IgG seropositive rats produced localized NMO pathology in brain, with characteristic astrocyte injury, inflammation, and demyelination after 5 days. Pathology was not seen when complement was inhibited, when non-NMO human IgG was administered instead of AQP4-IgG, or in AQP4-IgG seropositive AQP4 knockout rats. NMO pathology was similarly created in cervical spinal cord in seropositive rats. These results establish a noninvasive, spatially targeted model of NMO in rats, and demonstrate that BBB permeabilization, without underlying injury or inflammation, is sufficient to create NMO pathology in AQP4-IgG seropositive rats.
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Affiliation(s)
| | - Matthew S Adams
- Department of Medicine and Physiology.,Thermal Therapy Research Group, Department of Radiation Oncology, University of California, San Francisco, California
| | - Peter D Jones
- Thermal Therapy Research Group, Department of Radiation Oncology, University of California, San Francisco, California
| | - Chris J Diederich
- Thermal Therapy Research Group, Department of Radiation Oncology, University of California, San Francisco, California
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30
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Weber-Adrian D, Kofoed RH, Chan JWY, Silburt J, Noroozian Z, Kügler S, Hynynen K, Aubert I. Strategy to enhance transgene expression in proximity of amyloid plaques in a mouse model of Alzheimer's disease. Theranostics 2019; 9:8127-8137. [PMID: 31754385 PMCID: PMC6857057 DOI: 10.7150/thno.36718] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/29/2019] [Indexed: 12/26/2022] Open
Abstract
Gene therapy can be designed to efficiently counter pathological features characteristic of neurodegenerative disorders. Here, we took advantage of the glial fibrillary acidic protein (GFAP) promoter to preferentially enhance transgene expression near plaques composed of amyloid-beta peptides (Aβ), a hallmark of Alzheimer's disease (AD), in the TgCRND8 mouse model of amyloidosis. Methods: The delivery of intravenously injected recombinant adeno-associated virus mosaic serotype 1/2 (rAAV1/2) to the cortex and hippocampus of TgCRND8 mice was facilitated using transcranial MRI-guided focused ultrasound in combination with microbubbles (MRIgFUS), which transiently and locally increases the permeability of the blood-brain barrier (BBB). rAAV1/2 expression of the reporter green fluorescent protein (GFP) under a GFAP promoter was compared to GFP expression driven by the constitutive human beta actin (HBA) promoter. Results: MRIgFUS targeting the cortex and hippocampus facilitated the entry of rAAV1/2 and GFP expression under the GFAP promoter was localized to GFAP-positive astrocytes. Adjacent to Aβ plaques where GFAP is upregulated, the volume, surface area, and fluorescence intensity of the transgene GFP were greater in rAAV1/2-GFAP-GFP compared to rAAV1/2-HBA-GFP treated animals. In peripheral organs, GFP expression was particularly strong in the liver, irrespective of the promoter. Conclusion: The GFAP promoter enhanced transgene expression in proximity of Aβ plaques in the brain of TgCRND8 mice, and it also resulted in significant expression in the liver. Future gene therapies for neurological disorders could benefit from using a GFAP promoter to regulate transgene expression in response to disease-induced astrocytic reactivity.
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31
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Scheetz L, Park KS, Li Q, Lowenstein PR, Castro MG, Schwendeman A, Moon JJ. Engineering patient-specific cancer immunotherapies. Nat Biomed Eng 2019; 3:768-782. [PMID: 31406259 PMCID: PMC6783331 DOI: 10.1038/s41551-019-0436-x] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 07/03/2019] [Indexed: 02/06/2023]
Abstract
Research into the immunological processes implicated in cancer has yielded a basis for the range of immunotherapies that are now considered the fourth pillar of cancer treatment (alongside surgery, radiotherapy and chemotherapy). For some aggressive cancers, such as advanced non-small-cell lung carcinoma, combination immunotherapies have resulted in unprecedented treatment efficacy for responding patients, and have become frontline therapies. Individualized immunotherapy, enabled by the identification of patient-specific mutations, neoantigens and biomarkers, and facilitated by advances in genomics and proteomics, promises to broaden the responder patient population. In this Perspective, we give an overview of immunotherapies leveraging engineering approaches, including the design of biomaterials, delivery strategies and nanotechnology solutions, for the realization of individualized cancer treatments such as nanoparticle vaccines customized with neoantigens, cell therapies based on patient-derived dendritic cells and T cells, and combinations of theranostic strategies. Developments in precision cancer immunotherapy will increasingly rely on the adoption of engineering principles.
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Affiliation(s)
- Lindsay Scheetz
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Kyung Soo Park
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Qiao Li
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Pedro R Lowenstein
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Maria G Castro
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Anna Schwendeman
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - James J Moon
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI, USA.
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA.
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
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32
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Abrahao A, Meng Y, Llinas M, Huang Y, Hamani C, Mainprize T, Aubert I, Heyn C, Black SE, Hynynen K, Lipsman N, Zinman L. First-in-human trial of blood-brain barrier opening in amyotrophic lateral sclerosis using MR-guided focused ultrasound. Nat Commun 2019; 10:4373. [PMID: 31558719 PMCID: PMC6763482 DOI: 10.1038/s41467-019-12426-9] [Citation(s) in RCA: 275] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/06/2019] [Indexed: 12/17/2022] Open
Abstract
MR-guided focused ultrasound (MRgFUS) is an emerging technology that can accurately and transiently permeabilize the blood-brain barrier (BBB) for targeted drug delivery to the central nervous system. We conducted a single-arm, first-in-human trial to investigate the safety and feasibility of MRgFUS-induced BBB opening in eloquent primary motor cortex in four volunteers with amyotrophic lateral sclerosis (ALS). Here, we show successful BBB opening using MRgFUS as demonstrated by gadolinium leakage at the target site immediately after sonication in all subjects, which normalized 24 hours later. The procedure was well-tolerated with no serious clinical, radiologic or electroencephalographic adverse events. This study demonstrates that non-invasive BBB permeabilization over the motor cortex using MRgFUS is safe, feasible, and reversible in ALS subjects. In future, MRgFUS can be coupled with promising therapeutics providing a targeted delivery platform in ALS.
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Affiliation(s)
- Agessandro Abrahao
- Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada. .,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada. .,Harquail Centre for Neuromodulation, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.
| | - Ying Meng
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Harquail Centre for Neuromodulation, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.,Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Maheleth Llinas
- Harquail Centre for Neuromodulation, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.,Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Yuexi Huang
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Clement Hamani
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Harquail Centre for Neuromodulation, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.,Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Todd Mainprize
- Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Isabelle Aubert
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 3H7, Canada
| | - Chinthaka Heyn
- Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Odette Cancer Research, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Sandra E Black
- Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3H7, Canada
| | - Kullervo Hynynen
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Odette Cancer Research, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, M5S 3H7, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, M5S 3H7, Canada
| | - Nir Lipsman
- Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Harquail Centre for Neuromodulation, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada.,Division of Neurosurgery, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
| | - Lorne Zinman
- Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, M4N 3M5, Canada
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33
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Montero AS, Bielle F, Goldwirt L, Lalot A, Bouchoux G, Canney M, Belin F, Beccaria K, Pradat PF, Salachas F, Boillée S, Lobsiger C, Lafon C, Chapelon JY, Carpentier A. Ultrasound-Induced Blood-Spinal Cord Barrier Opening in Rabbits. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:2417-2426. [PMID: 31248640 DOI: 10.1016/j.ultrasmedbio.2019.05.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 05/15/2019] [Accepted: 05/21/2019] [Indexed: 06/09/2023]
Abstract
The blood-spinal cord barrier (BSCB) considerably limits the delivery and efficacy of treatments for spinal cord diseases. The blood-brain barrier can be safely opened with low-intensity pulsed ultrasound when microbubbles are simultaneously administered intravenously. This technique was tested on the BSCB in a rabbit model in this work. Twenty-three segments of spinal cord were sonicated with a 1-MHz unfocused pulsed ultrasound device and compared with non-sonicated segments. BSCB disruption was assessed using Evan's blue dye (EBD) extravasation. Tolerance was assessed by histologic analysis. An increased EBD concentration indicating BSCB disruption was clearly observed in sonicated segments compared with controls (p = 0.004). On one animal, which received 10 sonications, repetitive BSCB disruptions revealed no evidence of cumulative toxicity. BSCB can be disrupted using an unfocused pulsed ultrasound device in combination with microbubbles without neurotoxicity even in case of repeated sonications.
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Affiliation(s)
- Anne-Sophie Montero
- Sorbonne Universite, Neurosurgery Department, AP-HP, Hopital de la Pitie Salpêtrière, Paris, France; Advanced Surgical Research Technology Laboratory, Sorbonne Universite, Paris, France
| | - Franck Bielle
- Sorbonne Universite, Department of Neuropathology, AP-HP, Hopital de la Pitie Salpêtrière, Paris, France
| | - Lauriane Goldwirt
- Pharmacology Department, AP-HP, Hopital de Saint-Louis, Paris, France
| | - Adrien Lalot
- Université Paris Descartes, Laboratoire de Recherches Biochirurgicales, Hôpital Européen Georges Pompidou, Paris, France
| | - Guillaume Bouchoux
- Advanced Surgical Research Technology Laboratory, Sorbonne Universite, Paris, France
| | - Michael Canney
- Advanced Surgical Research Technology Laboratory, Sorbonne Universite, Paris, France
| | - Florine Belin
- Sorbonne Universite, Endocrinology Department, AP-HP, Hopital de la Pitie Salpêtrière, Paris, France
| | - Kevin Beccaria
- Advanced Surgical Research Technology Laboratory, Sorbonne Universite, Paris, France; Universite Paris Descartes, Department of Pediatric Neurosurgery, AP-HP, Hopital Necker, Paris, France
| | - Pierre-François Pradat
- Centre de Reference Maladie Rare SLA, Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Paris, France; Sorbonne Université, CNRS, INSERM, Laboratoire d'Imagerie Biomédicale, Paris, France; Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute Ulster University, C-TRIC, Altnagelvin Hospital, Derry/Londonderry, United Kingdom
| | - François Salachas
- Centre de Reference Maladie Rare SLA, Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Severine Boillée
- Inserm U 1127, CNRS UMR 7225, Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Christian Lobsiger
- Inserm U 1127, CNRS UMR 7225, Sorbonne Université, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France
| | - Cyril Lafon
- LabTAU, INSERM, Centre Léon Bérard, Université Lyon 1, Lyon, France
| | | | - Alexandre Carpentier
- Sorbonne Universite, Neurosurgery Department, AP-HP, Hopital de la Pitie Salpêtrière, Paris, France; LabTAU, INSERM, Centre Léon Bérard, Université Lyon 1, Lyon, France.
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34
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Fletcher SMP, Ogrodnik N, O'Reilly MA. Enhanced Detection of Bubble Emissions Through the Intact Spine for Monitoring Ultrasound-Mediated Blood-Spinal Cord Barrier Opening. IEEE Trans Biomed Eng 2019; 67:1387-1396. [PMID: 31442968 DOI: 10.1109/tbme.2019.2936972] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE We previously developed short burst, phase keying (SBPK) focused ultrasound (FUS) to mitigate standing waves in the human vertebral canal. Here, we show microbubble emissions from these pulses can be detected through the human vertebral arch and that these pulses are effective for blood-spinal cord barrier (BSCB) opening. METHODS At f0 = 514 kHz, circulating microbubbles were sonicated through ex vivo human vertebrae (60 kPa-1 MPa) using a dual-aperture approach and SBPK exposures engineered to incorporate pulse inversion (PI). Signals from a 250 kHz receiver were analyzed using PI, short-time Fourier analysis and the maximum projection over the pulse train. In rats (n = 14), SBPK FUS+microbubbles was applied to 3 locations/spinal cord at fixed pressures (∼0.20-0.47 MPa). MRI and histology were used to assess opening and tissue damage. RESULTS In human vertebrae between 0.2-0.4 MPa, PI amplified the microbubble/baseline ratio at f0/2 and 2f0 by 202 ± 40% (132-291%). This was maximal at 0.4 MPa, coinciding with the onset of broadband emissions. In vivo, opening was achieved at 40/42 locations, with mean MRI enhancement of 46 ± 32%(16%-178%). Using PI, f0/2 was detected at 14/40 opening locations. At the highest pressures (f0/2 present) histology showed widespread bleeding throughout the focal region. At the lowest pressures, opening was achieved without bleeding. CONCLUSION This study confirmed that PI can increase sensitivity to transvertebral detection of microbubble signals. Preliminary in vivo investigations show that SBPK FUS can increase BSCB permeability without tissue damage. SIGNIFICANCE SBPK is a clinically relevant pulse scheme and, in combination with PI, provides a means of mediating and monitoring BSCB opening noninvasively.
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Abstract
Treatment of certain central nervous system disorders, including different types of cerebral malignancies, is limited by traditional oral or systemic administrations of therapeutic drugs due to possible serious side effects and/or lack of the brain penetration and, therefore, the efficacy of the drugs is diminished. During the last decade, several new technologies were developed to overcome barrier properties of cerebral capillaries. This review gives a short overview of the structural elements and anatomical features of the blood–brain barrier. The various in vitro (static and dynamic), in vivo (microdialysis), and in situ (brain perfusion) blood–brain barrier models are also presented. The drug formulations and administration options to deliver molecules effectively to the central nervous system (CNS) are presented. Nanocarriers, nanoparticles (lipid, polymeric, magnetic, gold, and carbon based nanoparticles, dendrimers, etc.), viral and peptid vectors and shuttles, sonoporation and microbubbles are briefly shown. The modulation of receptors and efflux transporters in the cell membrane can also be an effective approach to enhance brain exposure to therapeutic compounds. Intranasal administration is a noninvasive delivery route to bypass the blood–brain barrier, while direct brain administration is an invasive mode to target the brain region with therapeutic drug concentrations locally. Nowadays, both technological and mechanistic tools are available to assist in overcoming the blood–brain barrier. With these techniques more effective and even safer drugs can be developed for the treatment of devastating brain disorders.
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Noroozian Z, Xhima K, Huang Y, Kaspar BK, Kügler S, Hynynen K, Aubert I. MRI-Guided Focused Ultrasound for Targeted Delivery of rAAV to the Brain. Methods Mol Biol 2019; 1950:177-197. [PMID: 30783974 DOI: 10.1007/978-1-4939-9139-6_10] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Recombinant adeno-associated viral (rAAV) vectors are a promising tool for therapeutic gene delivery to the brain. However, the delivery of rAAVs across the blood-brain barrier (BBB) and entry into the brain remains a major challenge for rAAV-based gene therapy. To circumvent this limitation, transcranial MRI-guided focused ultrasound (MRIgFUS) combined with intravenously injected microbubbles has been used to transiently and reversibly increase BBB permeability in targeted brain regions. Systemic administration of rAAVs at the time of sonication with focused ultrasound (FUS) facilitates the passage of rAAVs through the BBB and into the brain parenchyma. We and others have demonstrated that FUS-mediated rAAV delivery to the brain results in efficient transduction and transgene expression in vivo. Using this approach, the dose of intravenously injected rAAV variants that can cross the BBB can be reduced by 100 times, achieving significant transgene expression in the brain parenchyma with reduced peripheral transduction. Moreover, this strategy can be used to deliver rAAV variants that do not cross the BBB from the blood to selected brain regions. Here, we provide a detailed protocol for FUS-induced BBB permeability for targeted rAAV delivery to the brain of adult mice and rats.
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Affiliation(s)
- Zeinab Noroozian
- Brain Sciences, Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Kristiana Xhima
- Brain Sciences, Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Yuexi Huang
- Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada
| | | | - Sebastian Kügler
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Kullervo Hynynen
- Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Isabelle Aubert
- Brain Sciences, Biological Sciences, Sunnybrook Research Institute, Toronto, ON, Canada. .,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
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Fletcher SMP, O’Reilly MA. Analysis of Multifrequency and Phase Keying Strategies for Focusing Ultrasound to the Human Vertebral Canal. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2018; 65:2322-2331. [PMID: 30273151 PMCID: PMC6309482 DOI: 10.1109/tuffc.2018.2872171] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Focused ultrasound has been shown to increase the permeability of the blood-brain barrier and its feasibility for opening the blood-spinal cord barrier has also been demonstrated in small animal models, with great potential to impact the treatment of spinal cord (SC) disorders. For clinical translation, challenges to transvertebral focusing of ultrasound energy on the human spinal canal, such as a focal depth of field and standing-wave formation, must be addressed. A dual-aperture approach using multifrequency and phase-shift keying (PSK) strategies for achieving a controlled focus in human thoracic vertebrae was investigated through numerical simulations and benchtop experiments in ex vivo human vertebrae. An ~85% reduction in the focal depth of field was achieved compared to a single-aperture approach at 564 kHz. Short-burst (two-cycle) excitations in combination with PSK were found to suppress the formation of standing waves in ex vivo human thoracic vertebrae when focusing through the vertebral laminae. The results make an important contribution toward the development of a clinical-scale approach for targeting ultrasound therapy to the SC.
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Affiliation(s)
- Stecia-Marie P. Fletcher
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto,
ON, Canada and the Department of Medical Biophysics, University of Toronto,
ON, Canada ()
| | - Meaghan A. O’Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto,
ON, Canada and the Department of Medical Biophysics, University of Toronto,
ON, Canada ()
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Xhima K, Nabbouh F, Hynynen K, Aubert I, Tandon A. Noninvasive delivery of an α-synuclein gene silencing vector with magnetic resonance-guided focused ultrasound. Mov Disord 2018; 33:1567-1579. [PMID: 30264465 DOI: 10.1002/mds.101] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/20/2018] [Accepted: 06/25/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The characteristic progression of Lewy pathology in Parkinson's disease likely involves intercellular exchange and the accumulation of misfolded α-synuclein amplified by a prion-like self-templating mechanism. Silencing of the α-synuclein gene could provide long-lasting disease-modifying benefits by reducing the requisite substrate for the spreading aggregation. OBJECTIVES As a result of the poor penetration of viral vectors across the blood-brain barrier, gene therapy for central nervous system disorders requires direct injections into the affected brain regions, and invasiveness is further increased by the need for bilateral delivery to multiple brain regions. Here we test a noninvasive approach by combining low-intensity magnetic resonance-guided focused ultrasound and intravenous microbubbles that can transiently increase the access of brain impermeant therapeutic macromolecules to targeted brain regions. METHODS Transgenic mice expressing human α-synuclein were subjected to magnetic resonance-guided focused ultrasound targeted to 4 brain regions (hippocampus, substantia nigra, olfactory bulb, and dorsal motor nucleus) in tandem with intravenous microbubbles and an adeno-associated virus serotype 9 vector bearing a short hairpin RNA sequence targeting the α-synuclein gene. RESULTS One month following treatment, α-synuclein immunoreactivity was decreased in targeted brain regions, whereas other neuronal markers such as synaptophysin or tyrosine hydroxylase were unchanged, and cell death and glial activation remained at basal levels. CONCLUSIONS These results demonstrate that magnetic resonance-guided focused ultrasound can effectively, noninvasively, and simultaneously deliver viral vectors targeting α-synuclein to multiple brain areas. Importantly, this approach may be useful to alter the progression of Lewy pathology along selected neuronal pathways, particularly as prodromal PD markers improve early diagnoses. © 2018 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Kristiana Xhima
- Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Fadl Nabbouh
- Tanz Centre for Research in Neurodegenerative Diseases, Toronto, Ontario, Canada
| | - Kullervo Hynynen
- Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Isabelle Aubert
- Sunnybrook Research Institute, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Anurag Tandon
- Tanz Centre for Research in Neurodegenerative Diseases, Toronto, Ontario, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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Toccaceli G, Delfini R, Colonnese C, Raco A, Peschillo S. Emerging Strategies and Future Perspective in Neuro-Oncology Using Transcranial Focused Ultrasonography Technology. World Neurosurg 2018; 117:84-91. [DOI: 10.1016/j.wneu.2018.05.239] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/30/2018] [Accepted: 05/31/2018] [Indexed: 01/08/2023]
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Hallam KA, Donnelly EM, Karpiouk AB, Hartman RK, Emelianov SY. Laser-activated perfluorocarbon nanodroplets: a new tool for blood brain barrier opening. BIOMEDICAL OPTICS EXPRESS 2018; 9:4527-4538. [PMID: 30615730 PMCID: PMC6157760 DOI: 10.1364/boe.9.004527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/08/2018] [Accepted: 08/20/2018] [Indexed: 05/03/2023]
Abstract
A major obstacle in the monitoring and treatment of neurological diseases is the blood brain barrier (BBB), a semipermeable barrier that prevents the delivery of many therapeutics and imaging contrast agents to the brain. In this work, we explored the possibility of laser-activated perfluorocarbon nanodroplets (PFCnDs) to open the BBB and deliver agents to the brain tissue. Specifically, near infrared (NIR) dye-loaded PFCnDs comprised of a perfluorocarbon (PFC) core with a boiling point above physiological temperature were repeatedly vaporized and recondensed from liquid droplet to gas bubble under pulsed laser excitation. As a result, this pulse-to-pulse repeated behavior enabled the recurring interaction of PFCnDs with the endothelial lining of the BBB, allowing for a BBB opening and extravasation of dye into the brain tissue. The blood brain barrier opening and delivery of agents to tissue was confirmed on the macro and the molecular level by evaluating Evans Blue staining, ultrasound-guided photoacoustic (USPA) imaging, and histological tissue analysis. The demonstrated PFCnD-assisted pulsed laser method for BBB opening, therefore, represents a tool that has the potential to enable non-invasive, cost-effective, and efficient image-guided delivery of contrast and therapeutic agents to the brain.
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Affiliation(s)
- Kristina A. Hallam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA, USA
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Eleanor M. Donnelly
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Andrei B. Karpiouk
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Robin K. Hartman
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Stanislav Y. Emelianov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA, USA
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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McMahon D, Mah E, Hynynen K. Angiogenic response of rat hippocampal vasculature to focused ultrasound-mediated increases in blood-brain barrier permeability. Sci Rep 2018; 8:12178. [PMID: 30111814 PMCID: PMC6093874 DOI: 10.1038/s41598-018-30825-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/06/2018] [Indexed: 01/12/2023] Open
Abstract
Focused ultrasound (FUS) and circulating microbubbles can induce a targeted and transient increase in blood-brain barrier permeability. While preclinical research has demonstrated the utility of FUS for efficacious drug deliver to the brain, there remain gaps in our knowledge regarding the long-term response of brain vasculature to this intervention. Previous work has demonstrated transcriptional changes in hippocampal microvessels following sonication that are indicative of the initiation of angiogenic processes. Moreover, blood vessel growth has been reported in skeletal muscle following application of FUS and microbubbles. The current study demonstrates that blood vessel density in the rat hippocampus is modestly elevated at 7 and 14 d post-FUS compared to the contralateral hemisphere (7 d: 10.9 ± 6.0%, p = 0.02; 14 d: 12.1 ± 3.2%, p < 0.01), but returns to baseline by 21 d (5.9 ± 2.6%, p = 0.12). Concurrently, relative newborn endothelial cell density and frequency of small blood vessel segments were both elevated in the sonicated hippocampus. While further work is required to determine the mechanisms driving these changes, the findings presented here may have relevance to the optimal frequency of repeated treatments.
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Affiliation(s)
- Dallan McMahon
- Sunnybrook Research Institute, Toronto, M4N 3M5, Canada. .,University of Toronto, Department of Medical Biophysics, Toronto, M4N 3M5, Canada.
| | - Ethan Mah
- Sunnybrook Research Institute, Toronto, M4N 3M5, Canada
| | - Kullervo Hynynen
- Sunnybrook Research Institute, Toronto, M4N 3M5, Canada.,University of Toronto, Department of Medical Biophysics, Toronto, M4N 3M5, Canada.,University of Toronto, Institute of Biomaterials and Biomedical Engineering, Toronto, M5S 3G9, Canada
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42
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Xu R, O'Reilly MA. Simulating transvertebral ultrasound propagation with a multi-layered ray acoustics model. Phys Med Biol 2018; 63:145017. [PMID: 29947618 DOI: 10.1088/1361-6560/aacf75] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The simulation accuracy of transvertebral ultrasound propagation using a multi-layered ray acoustics model based on CT-derived vertebral geometry was investigated through comparison with experimental measurements of pressure fields in ex vivo human vertebral foramen. A spherically focused transducer (5 cm diameter, f-number 1.2, 514 kHz) was geometrically focused to the centre of individual thoracic vertebral foramen, through the posterior bony elements. Transducer propagation paths through the laminae and the spinous processes were tested. Simulation transducer-vertebra configurations were registered to experiment transducer-vertebra configurations, and simulation accuracy of the simulation model was evaluated for predicting maximum transmitted pressure to the canal, voxel pressure in the canal, and focal distortion. Accuracy in predicting maximum transmitted pressure was calculated by vertebra, and it is shown that simulation predicts maximum pressure with a greater degree of accuracy than a vertebra-specific insertion loss. Simulation error in voxel pressure was evaluated using root-mean-square error and cross-correlation, and found to be similar to the water-only case. Simulation accuracy in predicting focal distortion was evaluated by comparing experiment and simulation maximum pressure location and weighted >50% focal volume location. Average simulation error across all measurements and simulations in maximum pressure location and weighted >50% focal volume location were 2.3 mm and 1.5 mm, respectively. These errors are small relative to the dimensions of the transducer focus (4.9 mm full width half maximum), the spinal cord (10 mm diameter), and vertebral canal diameter (15-20 mm diameter). These results suggest that ray acoustics can be applied to simulating transvertebral ultrasound propagation.
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Affiliation(s)
- Rui Xu
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada. Department of Medical Biophysics, Faculty of Medicine, University of Toronto, 101 College Street Suite 15-701, Toronto, ON M5G 1L7, Canada. Author to whom any correspondence should be addressed
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O'Reilly MA, Chinnery T, Yee ML, Wu SK, Hynynen K, Kerbel RS, Czarnota GJ, Pritchard KI, Sahgal A. Preliminary Investigation of Focused Ultrasound-Facilitated Drug Delivery for the Treatment of Leptomeningeal Metastases. Sci Rep 2018; 8:9013. [PMID: 29899537 PMCID: PMC5998139 DOI: 10.1038/s41598-018-27335-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/31/2018] [Indexed: 12/21/2022] Open
Abstract
Leptomeningeal metastases (LM) are a serious complication of cancer in the central nervous system (CNS) and are diagnosed in approximately 5% of patients with solid tumors. Effective treatment using systemically administered therapeutics is hindered by the barriers of the CNS. Ultrasound can mediate delivery of drugs through these barriers. The goal of this study was to test the feasibility of using ultrasound-mediated drug delivery to improve the treatment of LM. LM was induced in the spinal cord of athymic rats by injecting HER2-expressing breast cancer cells into the subarachnoid space of the thoracic spine. Animals were divided into three groups: no treatment (n = 5), trastuzumab only (n = 6) or trastuzumab + focused ultrasound + microbubbles (FUS + MBs) (n = 7). Animals in groups 2 and 3 were treated weekly with intravenous trastuzumab +/− FUS + MBs for three weeks. Suppression in tumor growth was qualitatively observed by MRI in the group receiving ultrasound, and was confirmed by a significant difference in the tumor volume measured from the histology data (25 ± 17 mm3 vs 8 ± 5 mm3, p = 0.04 in the trastuzumab-only vs trastuzumab + FUS + MBs). This pilot study demonstrates the potential of ultrasound-mediated drug delivery as a novel treatment for LM. Future studies will extend this work to larger cohorts and the investigation of LM arising from other cancers.
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Affiliation(s)
- Meaghan A O'Reilly
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada. .,Department of Medical Biophysics, University of Toronto, Toronto, Canada.
| | - Tricia Chinnery
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - My-Linh Yee
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - Sheng-Kai Wu
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Kullervo Hynynen
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Robert S Kerbel
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Biological Sciences Platform, Sunnybrook Research Institute, Toronto, Canada
| | - Gregory J Czarnota
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Canada
| | - Kathleen I Pritchard
- Evaluative Clinical Sciences, Sunnybrook Health Sciences Centre, Toronto, Canada.,Medical Oncology, Sunnybrook Health Sciences Centre, Toronto, Canada.,Department of Medicine, University of Toronto, Toronto, Canada
| | - Arjun Sahgal
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada.,Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Canada
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Bing C, Hong Y, Hernandez C, Rich M, Cheng B, Munaweera I, Szczepanski D, Xi Y, Bolding M, Exner A, Chopra R. Characterization of different bubble formulations for blood-brain barrier opening using a focused ultrasound system with acoustic feedback control. Sci Rep 2018; 8:7986. [PMID: 29789589 PMCID: PMC5964106 DOI: 10.1038/s41598-018-26330-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 05/04/2018] [Indexed: 11/09/2022] Open
Abstract
Focused ultrasound combined with bubble-based agents serves as a non-invasive way to open the blood-brain barrier (BBB). Passive acoustic detection was well studied recently to monitor the acoustic emissions induced by the bubbles under ultrasound energy, but the ability to perform reliable BBB opening with a real-time feedback control algorithm has not been fully evaluated. This study focuses on characterizing the acoustic emissions of different types of bubbles: Optison, Definity, and a custom-made nanobubble. Their performance on reliable BBB opening under real-time feedback control based on acoustic detection was evaluated both in-vitro and in-vivo. The experiments were conducted using a 0.5 MHz focused ultrasound transducer with in-vivo focal pressure ranges from 0.1-0.7 MPa. Successful feedback control was achieved with all three agents when combining with infusion injection. Localized opening was confirmed with Evans blue dye leakage. Microscopic images were acquired to review the opening effects. Under similar total gas volume, nanobubble showed a more reliable opening effect compared to Optison and Definity (p < 0.05). The conclusions obtained from this study confirm the possibilities of performing stable opening using a feedback control algorithm combined with infusion injection. It also opens another potential research area of BBB opening using sub-micron bubbles.
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Affiliation(s)
- Chenchen Bing
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Yu Hong
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | - Megan Rich
- Division of Advanced Medical Imaging Research, University of Alabama, Birmingham, AL, 35294, USA
| | - Bingbing Cheng
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Imalka Munaweera
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Debra Szczepanski
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Yin Xi
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Department of Clinical Science, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Mark Bolding
- Division of Advanced Medical Imaging Research, University of Alabama, Birmingham, AL, 35294, USA
| | - Agata Exner
- Department of Radiology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Rajiv Chopra
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA.,Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, 75390, USA
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45
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Yue P, Miao W, Gao L, Zhao X, Teng J. Ultrasound-Triggered Effects of the Microbubbles Coupled to GDNF Plasmid-Loaded PEGylated Liposomes in a Rat Model of Parkinson's Disease. Front Neurosci 2018; 12:222. [PMID: 29686604 PMCID: PMC5900787 DOI: 10.3389/fnins.2018.00222] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/20/2018] [Indexed: 01/07/2023] Open
Abstract
Background: The purpose of this study was to investigate ultrasound-triggered effects of PEGylated liposomes-coupled microbubbles mediated gene transfer of glial cell line-derived neurotrophic factor (GDNF) plasmid (PLs-GDNF-MBs) on behavioral deficits and neuron loss in a rat model of Parkinson's disease (PD). Methods: The unloaded PLs-MBs were characterized for particle size, concentration and zeta potential. PD rat model was established by a unilateral 6-hydroxydopamine (6-OHDA) lesion. Rotational, climbing pole, and suspension tests were used to evaluate behavioral deficits. The immunohistochemical staining of tyrosine hydroxylase (TH) and dopamine transporter (DAT) was used to assess the neuron loss. The expression levels of GDNF and nuclear receptor-related factor 1 (Nurr1) were determined by western blot and qRT-PCR analysis. Results: The particle size of PLs-MBs was gradually increased, while the concentration and absolute zeta potential were gradually decreased in a time-dependent manner after injection. 6-OHDA elevated amphetamine-induced rotations and decreased the TH and DAT immunoreactivity compared to sham group. However, these effects were blocked by the PLs-GDNF-MBs. In addition, the mRNA and protein expression levels of GDNF and Nurr1 were increased after PLs-GDNF-MBs treatment. Conclusions: The delivery of PLs-GDNF-MBs into the brains using MRI-guided focused ultrasound alleviates the behavioral deficits and neuron loss in the rat model of PD.
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Affiliation(s)
- Peijian Yue
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Wang Miao
- Department of Neurological Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Lin Gao
- Department of Neurological Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xinyu Zhao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Junfang Teng
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Gene-Based Neuromodulation. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00030-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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47
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McMahon D, Hynynen K. Acute Inflammatory Response Following Increased Blood-Brain Barrier Permeability Induced by Focused Ultrasound is Dependent on Microbubble Dose. Theranostics 2017; 7:3989-4000. [PMID: 29109793 PMCID: PMC5667420 DOI: 10.7150/thno.21630] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/10/2017] [Indexed: 02/07/2023] Open
Abstract
Rationale: Focused ultrasound (FUS), in conjunction with circulating microbubbles (MBs), can be used to transiently increase the permeability of the blood-brain barrier (BBB) in a targeted manner, allowing therapeutic agents to enter the brain from systemic circulation. While promising preclinical work has paved the way for the initiation of 3 human trials, there remains concern regarding neuroinflammation following treatment. The aim of this study was to assess the magnitude of this response following sonication and explore the influence of MB dose. Methods: Differential expression of NFκB signaling pathway genes was assessed in rats at 6 h and 4 days following a FUS-mediated increase in BBB permeability. Three sonication schemes were tested: (1) a clinical imaging dose of MBs + peak negative pressure (PNP) controlled by acoustic feedback, (2) 10x clinical imaging dose of MBs + constant PNP of 0.290 MPa, and (3) 10x clinical imaging dose of MBs + PNP controlled by acoustic feedback. Follow-up magnetic resonance imaging (MRI) was performed to assess edema and hemorrhage. Hematoxylin and eosin histology was used to evaluate general tissue health. Results: MB dose has a significant impact on the expression of several key genes involved in acute inflammation and immune activation, including Tnf, Birc3, and Ccl2. At a clinical imaging dose of MBs, there were no significant changes detected in the expression of any NFκB signaling pathway genes. Conversely, a high MB dose resulted in a clear activation of the NFκB signaling pathway, accompanied by edema, neuronal degeneration, neutrophil infiltration, and microhemorrhage. Results also suggest that post-FUS gadolinium enhancement may hold predictive value in assessing the magnitude of inflammatory response. Conclusion: While a significant and damaging inflammatory response was observed at high MB doses, it was demonstrated that FUS can be used to induce increased BBB permeability without an associated upregulation of NFκB signaling pathway gene expression. This emphasizes the importance of employing optimized FUS parameters to mitigate the chances of causing injury to the brain at the targeted locations.
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Affiliation(s)
- Dallan McMahon
- University of Toronto, Department of Medical Biophysics, Toronto, M4N 3M5, Canada
- Sunnybrook Research Institute, Toronto, M4N 3M5, Canada
| | - Kullervo Hynynen
- University of Toronto, Department of Medical Biophysics, Toronto, M4N 3M5, Canada
- Sunnybrook Research Institute, Toronto, M4N 3M5, Canada
- University of Toronto, Institute of Biomaterials and Biomedical Engineering, Toronto, M5S 3G9, Canada
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Payne AH, Hawryluk GW, Anzai Y, Odéen H, Ostlie MA, Reichert EC, Stump AJ, Minoshima S, Cross DJ. Magnetic resonance imaging-guided focused ultrasound to increase localized blood-spinal cord barrier permeability. Neural Regen Res 2017; 12:2045-2049. [PMID: 29323044 PMCID: PMC5784353 DOI: 10.4103/1673-5374.221162] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Spinal cord injury (SCI) affects thousands of people every year in the USA, and most patients are left with some permanent paralysis. Therapeutic options are limited and only modestly affect outcome. To address this issue, we used magnetic resonance imaging-guided focused ultrasound (MRgFUS) as a non-invasive approach to increase permeability in the blood-spinal cord barrier (BSCB). We hypothesize that localized, controlled sonoporation of the BSCB by MRgFUS will aid delivery of therapeutics to the injury. Here, we report our preliminary findings for the ability of MRgFUS to increase BSCB permeability in the thoracic spinal cord of a normal rat model. First, an excised portion of normal rat spinal column was used to characterize the acoustic field and to estimate the insertion losses that could be expected in an MRgFUS blood spinal cord barrier opening. Then, in normal rats, MRgFUS was applied in combination with intravenously administered microbubbles to the spinal cord region. Permeability of the BSCB was indicated as signal enhancement by contrast administered prior to T1-weighted magnetic resonance imaging and verified by Evans blue dye. Neurological testing using the Basso, Beattie, and Breshnahan scale and the ladder walk was normal in 8 of 10 rats tested. Two rats showed minor impairment indicating need for further refinement of parameters. No gross tissue damage was evident by histology. In this study, we have opened successfully the blood spinal cord barrier in the thoracic region of the normal rat spine using magnetic resonance-guided focused ultrasound combined with microbubbles.
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Affiliation(s)
- Allison H Payne
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | | | - Yoshimi Anzai
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Henrik Odéen
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Megan A Ostlie
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Ethan C Reichert
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - Amanda J Stump
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Satoshi Minoshima
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Donna J Cross
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
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Ellens NPK, Partanen A. Preclinical MRI-Guided Focused Ultrasound: A Review of Systems and Current Practices. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:291-305. [PMID: 27662675 DOI: 10.1109/tuffc.2016.2609238] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Effective preclinical research is a vital component in the development of MRI-guided focused ultrasound (MRgFUS) and its translation to clinic. In this review, we seek to outline the challenges at hand for effective preclinical research, survey different solutions, and underline best practices. Furthermore, we summarize efforts to build and characterize dedicated preclinical MRgFUS equipment, including lab prototypes and available commercial products. Finally, we discuss constraints and considerations specific to using clinical MRgFUS equipment in preclinical research. Specifically, we examine additional hardware that has been used to adapt clinical MRgFUS equipment to better position, constrain, and image preclinical subjects, as well as software solutions that have been used to extend the potential and capabilities of clinical devices.
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50
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Fu H, McCarty DM. Crossing the blood–brain-barrier with viral vectors. Curr Opin Virol 2016; 21:87-92. [DOI: 10.1016/j.coviro.2016.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 08/08/2016] [Accepted: 08/09/2016] [Indexed: 02/05/2023]
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