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López-Aguirre M, Castillo-Ortiz M, Viña-González A, Blesa J, Pineda-Pardo JA. The road ahead to successful BBB opening and drug-delivery with focused ultrasound. J Control Release 2024; 372:901-913. [PMID: 38971426 DOI: 10.1016/j.jconrel.2024.07.006] [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: 04/16/2024] [Revised: 06/26/2024] [Accepted: 07/03/2024] [Indexed: 07/08/2024]
Abstract
This review delves into the innovative technology of Blood-Brain Barrier (BBB) opening with low-intensity focused ultrasound in combination with microbubbles (LIFU-MB), a promising therapeutic modality aimed at enhancing drug delivery to the central nervous system (CNS). The BBB's selective permeability, while crucial for neuroprotection, significantly hampers the efficacy of pharmacological treatments for CNS disorders. LIFU-MB emerges as a non-invasive and localized method to transiently increase BBB permeability, facilitating the delivery of therapeutic molecules. Here, we review the procedural stages of LIFU-MB interventions, including planning and preparation, sonication, evaluation, and delivery, highlighting the technological diversity and methodological challenges encountered in current clinical applications. With an emphasis on safety and efficacy, we discuss the crucial aspects of ultrasound delivery, microbubble administration, acoustic feedback monitoring and assessment of BBB permeability. Finally, we explore the critical choices for effective BBB opening with LIFU-MB, focusing on selecting therapeutic agents, optimizing delivery methods, and timing for delivery. Overcoming existing barriers to integrate this technology into clinical practice could potentially revolutionize CNS drug delivery and treatment paradigms in the near future.
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Affiliation(s)
- Miguel López-Aguirre
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Instituto de Investigación Sanitaria HM Hospitales, Spain; PhD Program in Physics, Complutense University of Madrid, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Castillo-Ortiz
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Instituto de Investigación Sanitaria HM Hospitales, Spain; PhD Program in Technologies for Health and Well-being, Polytechnic University of Valencia, Valencia, Spain; Molecular Imaging Technologies Research Institute (I3M), Polytechnic University of Valencia, Valencia, Spain
| | - Ariel Viña-González
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Instituto de Investigación Sanitaria HM Hospitales, Spain; PhD Program in Biomedical Engineering, Polytechnic University of Madrid, Madrid, Spain
| | - Javier Blesa
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Instituto de Investigación Sanitaria HM Hospitales, Spain; Facultad HM de Ciencias de la Salud de la Universidad Camilo José Cela, Madrid, Spain
| | - José A Pineda-Pardo
- HM CINAC (Centro Integral de Neurociencias Abarca Campal), Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain; Instituto de Investigación Sanitaria HM Hospitales, Spain.
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2
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Gattegno R, Arbel L, Riess N, Shinar H, Katz S, Ilovitsh T. Enhanced capillary delivery with nanobubble-mediated blood-brain barrier opening and advanced high resolution vascular segmentation. J Control Release 2024; 369:506-516. [PMID: 38575074 DOI: 10.1016/j.jconrel.2024.04.001] [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: 12/18/2023] [Revised: 03/28/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024]
Abstract
Overcoming the blood-brain barrier (BBB) is essential to enhance brain therapy. Here, we utilized nanobubbles with focused ultrasound for targeted and improved BBB opening in mice. A microscopy technique method assessed BBB opening at a single blood vessel resolution employing a dual-dye labeling technique using green fluorescent molecules to label blood vessels and Evans blue brain-impermeable dye for quantifying BBB extravasation. A deep learning architecture enabled blood vessels segmentation, delivering comparable accuracy to manual segmentation with a significant time reduction. Segmentation outcomes were applied to the Evans blue channel to quantify extravasation of each blood vessel. Results were compared to microbubble-mediated BBB opening, where reduced extravasation was observed in capillaries with a diameter of 2-6 μm. In comparison, nanobubbles yield an improved opening in these capillaries, and equivalent efficacy to that of microbubbles in larger vessels. These results indicate the potential of nanobubbles to serve as enhanced agents for BBB opening, amplifying bioeffects in capillaries while preserving comparable opening in larger vessels.
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Affiliation(s)
- Roni Gattegno
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Lilach Arbel
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Noa Riess
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Hila Shinar
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Sharon Katz
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Tali Ilovitsh
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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3
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Peko L, Katz S, Gattegno R, Ilovitsh T. Protocol to assess extravasation of fluorescent molecules in mice after ultrasound-mediated blood-brain barrier opening. STAR Protoc 2024; 5:102770. [PMID: 38160392 PMCID: PMC10805705 DOI: 10.1016/j.xpro.2023.102770] [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: 08/08/2023] [Revised: 10/26/2023] [Accepted: 11/22/2023] [Indexed: 01/03/2024] Open
Abstract
Blood-brain barrier disruption (BBBD) using focused ultrasound (FUS) and microbubbles (MBs) is an effective tool for therapeutic delivery to the brain. Here, we present an optimized protocol for quantifying fluorescent molecules extravasation in mice. We describe steps for ultrasound treatment, injection of MBs and fluorescent dyes, brain harvesting, microscopy imaging, and image postprocessing algorithm. Our protocol has proven to successfully conduct a diameter-dependent analysis that measures vascular leakage following FUS-mediated BBBD at a single blood vessel resolution. For complete details on the use and execution of this protocol, please refer to Katz et al.1.
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Affiliation(s)
- Lea Peko
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Sharon Katz
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Roni Gattegno
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Tali Ilovitsh
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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4
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Mano T, Grutman T, Ilovitsh T. Versatile Ultrasound-Compatible Microfluidic Platform for In Vitro Microvasculature Flow Research and Imaging Optimization. ACS OMEGA 2023; 8:47667-47677. [PMID: 38144052 PMCID: PMC10734021 DOI: 10.1021/acsomega.3c05849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/16/2023] [Accepted: 11/22/2023] [Indexed: 12/26/2023]
Abstract
Ultrasound localization microscopy (ULM) enables the creation of super-resolved images and velocity maps by localizing and tracking microbubble contrast agents through a vascular network over thousands of frames of ultrafast plane wave images. However, a significant challenge lies in developing ultrasound-compatible microvasculature phantoms to investigate microbubble flow and distribution in controlled environments. In this study, we introduce a new class of gelatin-based microfluidic-inspired phantoms uniquely tailored for ULM studies. These devices allow for the creation of complex and reproducible microvascular networks featuring channel diameters as small as 100 μm. Our experiments focused on microbubble behavior under ULM conditions within bifurcating and converging vessel phantoms. We evaluated the impact of bifurcation angles (25, 45, and 55°) and flow rates (0.01, 0.02, and 0.03 mL/min) on the acquisition time of branching channels. Additionally, we explored the saturation time effect of narrow channels branching off larger ones. Significantly longer acquisition times were observed for the narrow vessels, with an average increase of 72% when a 100 μm channel branched off from a 300 μm channel and an average increase of 90% for a 200 μm channel branching off from a 500 μm channel. The robustness of our fabrication method is demonstrated through the creation of two trifurcating microfluidic phantoms, including one that converges back into a single channel, a configuration that cannot be achieved through traditional methods. This new class of ULM phantoms serves as a versatile platform for noninvasively studying complex flow patterns using ultrasound imaging, unlocking new possibilities for in vitro microvasculature research and imaging optimization.
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Affiliation(s)
- Tamar Mano
- Department
of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tal Grutman
- Department
of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tali Ilovitsh
- Department
of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
- The
Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
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5
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Manuel TJ, Sigona MK, Phipps MA, Kusunose J, Luo H, Yang PF, Newton AT, Gore JC, Grissom W, Chen LM, Caskey CF. Small volume blood-brain barrier opening in macaques with a 1 MHz ultrasound phased array. J Control Release 2023; 363:707-720. [PMID: 37827222 DOI: 10.1016/j.jconrel.2023.10.015] [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: 06/05/2023] [Revised: 10/05/2023] [Accepted: 10/08/2023] [Indexed: 10/14/2023]
Abstract
The use of focused ultrasound to open the blood-brain barrier (BBB) has the potential to deliver drugs to specific regions of the brain. The size of the BBB opening and ability to localize the opening determines the spatial extent and is a limiting factor in many applications of BBB opening where targeting a small brain region is desired. Here we evaluate the performance of a system designed for small opening volumes and highlight the unique challenges associated with pushing the spatial precision of this technique. To achieve small volume openings in cortical regions of the macaque brain, we tested a custom 1 MHz array transducer integrated into a magnetic resonance image-guided focused ultrasound system. Using real-time cavitation monitoring, we demonstrated twelve instances of single sonication, small volume BBB opening with average volumes of 59 ± 37 mm3 and 184 ± 2 mm3 in cortical and subcortical targets, respectively. We found high correlation between subject-specific acoustic simulations and observed openings when incorporating grey matter segmentation (R2 = 0.8577), and the threshold for BBB opening based on simulations was 0.53 MPa. Analysis of MRI-based safety assessment and cavitation signals indicate a safe pressure range for 1 MHz BBB opening and suggest that our system can be used to deliver drugs and gene therapy to small brain regions.
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Affiliation(s)
- Thomas J Manuel
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Michelle K Sigona
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - M Anthony Phipps
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Jiro Kusunose
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Huiwen Luo
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Pai-Feng Yang
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Allen T Newton
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - William Grissom
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Li Min Chen
- Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA
| | - Charles F Caskey
- Vanderbilt University, Nashville, TN, USA; Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Nashville, TN, USA.
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6
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Gao P, Sun Y, Zhang G, Li C, Wang L. A transducer positioning method for transcranial focused ultrasound treatment of brain tumors. Front Neurosci 2023; 17:1277906. [PMID: 37904813 PMCID: PMC10613465 DOI: 10.3389/fnins.2023.1277906] [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: 08/15/2023] [Accepted: 09/28/2023] [Indexed: 11/01/2023] Open
Abstract
Purpose As a non-invasive method for brain diseases, transcranial focused ultrasound (tFUS) offers higher spatial precision and regulation depth. Due to the altered path and intensity of sonication penetrating the skull, the focus and intensity in the skull are difficult to determine, making the use of ultrasound therapy for cancer treatment experimental and not widely available. The deficiency can be effectively addressed by numerical simulation methods, which enable the optimization of sonication modulation parameters and the determination of precise transducer positioning. Methods A 3D skull model was established using binarized brain CT images. The selection of the transducer matrix was performed using the radius positioning (RP) method after identifying the intracranial target region. Simulations were performed, encompassing acoustic pressure (AP), acoustic field, and temperature field, in order to provide compelling evidence of the safety of tFUS in sonication-induced thermal effects. Results It was found that the angle of sonication path to the coronal plane obtained at all precision and frequency models did not exceed 10° and 15° to the transverse plane. The results of thermal effects illustrated that the peak temperatures of tFUS were 43.73°C, which did not reach the point of tissue degeneration. Once positioned, tFUS effectively delivers a Full Width at Half Maximum (FWHM) stimulation that targets tumors with diameters of up to 3.72 mm in a one-off. The original precision model showed an attenuation of 24.47 ± 6.13 mm in length and 2.40 ± 1.42 mm in width for the FWHM of sonication after penetrating the skull. Conclusion The vector angles of the sonication path in each direction were determined based on the transducer positioning results. It has been suggested that when time is limited for precise transducer positioning, fixing the transducer on the horizontal surface of the target region can also yield positive results for stimulation. This framework used a new transducer localization method to offer a reliable basis for further research and offered new methods for the use of tFUS in brain tumor-related research.
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Affiliation(s)
- Penghao Gao
- Artificial Intelligence Laboratory, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Yue Sun
- Department of Biomedical Engineering, Shenyang University of Technology, Shenyang, Liaoning, China
| | - Gongsen Zhang
- Artificial Intelligence Laboratory, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Chunsheng Li
- Department of Biomedical Engineering, Shenyang University of Technology, Shenyang, Liaoning, China
| | - Linlin Wang
- Artificial Intelligence Laboratory, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
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7
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Mondou P, Mériaux S, Nageotte F, Vappou J, Novell A, Larrat B. State of the art on microbubble cavitation monitoring and feedback control for blood-brain-barrier opening using focused ultrasound. Phys Med Biol 2023; 68:18TR03. [PMID: 37369229 DOI: 10.1088/1361-6560/ace23e] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/27/2023] [Indexed: 06/29/2023]
Abstract
Focused ultrasound (FUS) is a non-invasive and highly promising method for targeted and reversible blood-brain barrier permeabilization. Numerous preclinical studies aim to optimize the localized delivery of drugs using this method in rodents and non-human primates. Several clinical trials have been initiated to treat various brain diseases in humans using simultaneous BBB permeabilization and drug injection. This review presents the state of the art ofin vitroandin vivocavitation control algorithms for BBB permeabilization using microbubbles (MB) and FUS. Firstly, we describe the different cavitation states, their physical significance in terms of MB behavior and their translation into the spectral composition of the backscattered signal. Next, we report the different indexes calculated and used during the ultrasonic monitoring of cavitation. Finally, the differentin vitroandin vivocavitation control strategies described in the literature are presented and compared.
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Affiliation(s)
- Paul Mondou
- Université de Strasbourg, CNRS, ICube, UMR7357, Strasbourg, France
- Université Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, 91191, Gif-sur-Yvette, France
| | - Sébastien Mériaux
- Université Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, 91191, Gif-sur-Yvette, France
| | - Florent Nageotte
- Université de Strasbourg, CNRS, ICube, UMR7357, Strasbourg, France
| | - Jonathan Vappou
- Université de Strasbourg, CNRS, ICube, UMR7357, Strasbourg, France
| | - Anthony Novell
- Université Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, 91191, Gif-sur-Yvette, France
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, SHFJ, 91401 , Orsay, France
| | - Benoit Larrat
- Université Paris-Saclay, CEA, CNRS, BAOBAB, NeuroSpin, 91191, Gif-sur-Yvette, France
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8
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Katz S, Gattegno R, Peko L, Zarik R, Hagani Y, Ilovitsh T. Diameter-dependent assessment of microvascular leakage following ultrasound-mediated blood-brain barrier opening. iScience 2023; 26:106965. [PMID: 37378309 PMCID: PMC10291464 DOI: 10.1016/j.isci.2023.106965] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 05/01/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
Blood brain barrier disruption (BBBD) using focused ultrasound (FUS) and microbubbles (MB) is an effective tool for therapeutic delivery to the brain. BBBD depends to a great extent on MB oscillations. Because the brain vasculature is heterogenic in diameter, reduced MB oscillations in smaller blood vessels, together with a lower number of MBs in capillaries, can lead to variations in BBBD. Therefore, evaluating the impact of microvasculature diameter on BBBD is of great importance. We present a method to characterize molecules extravasation following FUS-mediated BBBD, at a single blood vessel resolution. Evans blue (EB) leakage was used as marker for BBBD, whereas blood vessels localization was done using FITC labeled Dextran. Automated image processing pipeline was developed to quantify the extent of extravasation as function of microvasculature diameter, including a wide range of vascular morphological parameters. Variations in MB vibrational response were observed in blood vessel mimicking fibers with varied diameters. Higher peak negative pressures (PNP) were required to initiate stable cavitation in fibers with smaller diameters. In vivo in the treated brains, EB extravasation increased as a function of blood vessel diameter. The percentage of strong BBBD blood vessels increased from 9.75% for 2-3 μm blood vessels to 91.67% for 9-10 μm. Using this method, it is possible to conduct a diameter-dependent analysis that measures vascular leakage resulting from FUS-mediated BBBD at a single blood vessel resolution.
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Affiliation(s)
- Sharon Katz
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Roni Gattegno
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Lea Peko
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Romario Zarik
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yulie Hagani
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Tali Ilovitsh
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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9
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Seo Y, Han S, Song BW, Chang JW, Na YC, Chang WS. Endogenous Neural Stem Cell Activation after Low-Intensity Focused Ultrasound-Induced Blood–Brain Barrier Modulation. Int J Mol Sci 2023; 24:ijms24065712. [PMID: 36982785 PMCID: PMC10056062 DOI: 10.3390/ijms24065712] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 03/08/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
Endogenous neural stem cells (eNSCs) in the adult brain, which have the potential to self-renew and differentiate into functional, tissue-appropriate cell types, have raised new expectations for neurological disease therapy. Low-intensity focused ultrasound (LIFUS)-induced blood–brain barrier modulation has been reported to promote neurogenesis. Although these studies have reported improved behavioral performance and enhanced expression of brain biomarkers after LIFUS, indicating increased neurogenesis, the precise mechanism remains unclear. In this study, we evaluated eNSC activation as a mechanism for neurogenesis after LIFUS-induced blood–brain barrier modulation. We evaluated the specific eNSC markers, Sox-2 and nestin, to confirm the activation of eNSCs. We also performed 3′-deoxy-3′[18F] fluoro-L-thymidine positron emission tomography ([18F] FLT-PET) to evaluate the activation of eNSCs. The expression of Sox-2 and nestin was significantly upregulated 1 week after LIFUS. After 1 week, the upregulated expression decreased sequentially; after 4 weeks, the upregulated expression returned to that of the control group. [18F] FLT-PET images also showed higher stem cell activity after 1 week. The results of this study indicated that LIFUS could activate eNSCs and induce adult neurogenesis. These results show that LIFUS may be useful as an effective treatment for patients with neurological damage or neurological disorders in clinical settings.
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Affiliation(s)
- Younghee Seo
- Department of Neurosurgery and Brain Research Institute, Yonsei University College of Medicine, Seodaemun-gu, Seoul 03722, Republic of Korea
- Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Sangheon Han
- Department of Neurosurgery and Brain Research Institute, Yonsei University College of Medicine, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Byeong-Wook Song
- Department for Medical Science, College of Medicine, Catholic Kwandong University, Gangwon-do, Gangneung City 25601, Republic of Korea
| | - Jin Woo Chang
- Department of Neurosurgery and Brain Research Institute, Yonsei University College of Medicine, Seodaemun-gu, Seoul 03722, Republic of Korea
- Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Young Cheol Na
- Department of Neurosurgery and Brain Research Institute, Yonsei University College of Medicine, Seodaemun-gu, Seoul 03722, Republic of Korea
- Department of Neurosurgery, Catholic Kwandong University College of Medicine, International St. Mary’s Hospital, Seo-gu, Incheon Metropolitan City 22711, Republic of Korea
- Correspondence: (Y.C.N.); (W.S.C.)
| | - Won Seok Chang
- Department of Neurosurgery and Brain Research Institute, Yonsei University College of Medicine, Seodaemun-gu, Seoul 03722, Republic of Korea
- Correspondence: (Y.C.N.); (W.S.C.)
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10
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Eck M, Aronovich R, Ilovitsh T. Efficacy optimization of low frequency microbubble-mediated sonoporation as a drug delivery platform to cancer cells. Int J Pharm X 2022; 4:100132. [PMID: 36189459 PMCID: PMC9520274 DOI: 10.1016/j.ijpx.2022.100132] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 09/21/2022] [Indexed: 11/20/2022] Open
Abstract
Ultrasound insonation of microbubbles can be used to form pores in cell membranes and facilitate the local trans-membrane transport of drugs and genes. An important factor in efficient delivery is the size of the delivered target compared to the generated membrane pores. Large molecule delivery remains a challenge, and can affect the resulting therapeutic outcomes. To facilitate large molecule delivery, large pores need to be formed. While ultrasound typically uses megahertz frequencies, it was recently shown that when microbubbles are excited at a frequency of 250 kHz (an order of magnitude below the resonance frequency of these agents), their oscillations are significantly enhanced as compared to the megahertz range. Here, to promote the delivery of large molecules, we suggest using this low frequency and inducing large pore formation through the high-amplitude oscillations of microbubbles. We assessed the impact of low frequency microbubble-mediated sonoporation on breast cancer cell uptake by optimizing the delivery of 4 fluorescent molecules ranging from 1.2 to 70 kDa in size. The optimal ultrasound peak negative pressure was found to be 500 kPa. Increasing the pressure did not enhance the fraction of fluorescent cells, and in fact reduced cell viability. For the smaller molecule sizes, 1.2 kDa and 4 kDa, the groups treated with an ultrasound pressure of 500 kPa and MB resulted in a fraction of 58% and 29% of fluorescent cells respectively, whereas delivery of 20 kDa and 70 kDa molecules yielded 10% and 5%, respectively. These findings suggest that low-frequency (e.g., 250 kHz) insonation of microbubbles results in high amplitude oscillation in vitro that increase the uptake of large molecules. Successful ultrasound-mediated molecule delivery requires the careful selection of insonation parameters to maximize the therapeutic effect by increasing cell uptake.
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Affiliation(s)
- Michal Eck
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ramona Aronovich
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tali Ilovitsh
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
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11
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Development of an ultrasound guided focused ultrasound system for 3D volumetric low energy nanodroplet-mediated histotripsy. Sci Rep 2022; 12:20664. [PMID: 36450815 PMCID: PMC9712369 DOI: 10.1038/s41598-022-25129-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/24/2022] [Indexed: 12/03/2022] Open
Abstract
Low pressure histotripsy is likely to facilitate current treatments that require extremely high pressures. An ultrasound guided focused ultrasound system was designed to accommodate a rotating imaging transducer within a low frequency therapeutic transducer that operates at a center frequency of 105 kHz. The implementation of this integrated system provides real-time therapeutic and volumetric imaging functions, that are used here for low-cost, low-energy 3D volumetric ultrasound histotripsy using nanodroplets. A two-step approach for low pressure histotripsy is implemented with this dual-array. Vaporization of nanodroplets into gaseous microbubbles was performed via the 1D rotating imaging probe. The therapeutic transducer is then used to detonate the vaporized nanodroplets and trigger potent mechanical effects in the surrounding tissue. Rotating the imaging transducer creates a circular vaporized nanodroplet shape which generates a round lesion upon detonation. This contrasts with the elongated lesion formed when using a standard 1D imaging transducer for nanodroplet activation. Optimization experiments show that maximal nanodroplet activation can be achieved with a 2-cycle excitation pulse at a center frequency of 3.5 MHz, and a peak negative pressure of 3.4 MPa (a mechanical index of 1.84). Vaporized nanodroplet detonation was achieved by applying a low frequency treatment at a center frequency of 105 kHz and mechanical index of 0.9. In ex-vivo samples, the rotated nanodroplet activation method yielded the largest lesion area, with a mean of 4.7 ± 0.5 mm2, and a rounded shape. In comparison, standard fixed transducer nanodroplet activation resulted in an average lesion area of 2.6 ± 0.4 mm2, and an elongated shape. This hybrid system enables to achieve volumetric low energy histotripsy, and thus facilitates the creation of precise, large-volume mechanical lesions in tissues, while reducing the pressure threshold required for standard histotripsy by over an order of magnitude.
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Zalloum IO, Paknahad AA, Kolios MC, Karshafian R, Tsai SSH. Controlled Shrinkage of Microfluidically Generated Microbubbles by Tuning Lipid Concentration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13021-13029. [PMID: 36260341 DOI: 10.1021/acs.langmuir.2c01439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Monodisperse microbubbles with diameters less than 10 μm are desirable in several ultrasound imaging and therapeutic delivery applications. However, conventional approaches to synthesize microbubbles, which are usually agitation-based, produce polydisperse bubbles that are less desirable because of their heterogeneous response when exposed to an ultrasound field. Microfluidics technology has the unique advantage of generating size-controlled monodisperse microbubbles, and it is now well established that the diameter of microfluidically made microbubbles can be tuned by varying the liquid flow rate, gas pressure, and dimensions of the microfluidic channel. It is also observed that once the microbubbles form, the bubbles shrink and eventually stabilize to a quasi-equilibrium diameter, and that the rate of stabilization is related to the lipid solution. However, how the lipid solution concentration affects the degree of bubble shrinkage, and the stable size of microbubbles, has not been thoroughly examined. Here, we investigate whether and how the lipid concentration affects the degree of microbubble shrinkage. Namely, we utilize a flow-focusing microfluidic geometry to generate monodisperse bubbles, and observe the effect of gas composition (2.5, 1.42, and 0.17 wt % octafluoropropane in nitrogen) and lipid concentration (1-16 mg/mL) on the degree of microbubble shrinkage. For the lipid system and gas utilized in these experiments, we observe a monotonic increase in the degree of microbubble shrinkage with decreasing lipid concentration, and no dependency on the gas composition. We hypothesize that the degree of shrinkage is related to lipid concentration by the self-assembly of lipids on the gas-liquid interface during bubble generation and subsequent lipid packing on the interface during shrinkage, which is arrested when a maximum packing density is achieved. We anticipate that this approach for creating and tuning the size of monodisperse microbubbles will find utility in biomedical applications, such as contrast-enhanced ultrasound imaging and ultrasound-triggered gene delivery.
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Affiliation(s)
- Intesar O Zalloum
- Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Ali A Paknahad
- Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Michael C Kolios
- Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Raffi Karshafian
- Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Scott S H Tsai
- Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
- Graduate Program in Biomedical Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
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13
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Wang Z, Pan Y, Huang H, Zhang Y, Li Y, Zou C, Huang G, Chen Y, Li Y, Li J, Chen H. Enhanced thrombolysis by endovascular low-frequency ultrasound with bifunctional microbubbles in venous thrombosis: in vitro and in vivo study. Front Bioeng Biotechnol 2022; 10:965769. [PMID: 35942007 PMCID: PMC9356075 DOI: 10.3389/fbioe.2022.965769] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
There is a need to improve the efficacy and safety of endovascular techniques in venous thrombotic diseases, and microbubble enhanced sonothrombolysis is a promising approach. However, whether endovascular low-frequency ultrasound (LFUS) can be utilized in microbubble enhanced sonothrombolysis is unclear. Here, we present a catheter-based thrombolytic system that combines unfocused low-frequency low-intensity ultrasound with novel fibrin-targeted drug-loaded bifunctional microbubbles. We develop an in vitro flow model and an in vivo rabbit inferior vena cava (IVC) thrombosis model to evaluate the safety and efficacy of the thrombolytic system. The results indicate that microbubble enhanced sonothrombolysis with endovascular LFUS treatment for 30 min is equally effective compared to pure pharmacologic treatment. Furthermore, the thrombolytic efficacy of this system is safely and substantially improved by the introduction of a fibrin-targeted drug-loaded bifunctional microbubble with a reduction of the fibrinolytic agent dosage by 60%. The microbubble enhanced endovascular LFUS sonothrombolysis system with excellent thrombolytic efficacy may serve as a new therapeutic approach for venous thrombotic diseases.
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Affiliation(s)
- Zhaojian Wang
- Department of Vascular Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yunfan Pan
- State Key Laboratory of Tribology, Tsinghua University, Beijing, China
| | - Huaigu Huang
- Department of Vascular Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuan Zhang
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
| | - Yan Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing, China
| | - Chenghong Zou
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
| | - Guanghua Huang
- Department of Vascular Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuexin Chen
- Department of Vascular Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- *Correspondence: Yuexin Chen, ; Yongjian Li,
| | - Yongjian Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing, China
- *Correspondence: Yuexin Chen, ; Yongjian Li,
| | - Jiang Li
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
| | - Haosheng Chen
- State Key Laboratory of Tribology, Tsinghua University, Beijing, China
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Glickstein B, Levron M, Shitrit S, Aronovich R, Feng Y, Ilovitsh T. Nanodroplet-Mediated Low-Energy Mechanical Ultrasound Surgery. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:1229-1239. [PMID: 35351316 DOI: 10.1016/j.ultrasmedbio.2022.02.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/08/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
Mechanical ultrasound surgery methods use short, high-intensity pulses to fractionate tissues. This study reports the development of a two-step technology for low-energy mechanical ultrasound surgery of tissues using nanodroplets to reduce the pressure threshold. Step 1 consists of vaporizing the nanodroplets into gaseous microbubbles via megahertz ultrasound excitation. Then, low-frequency ultrasound is applied to the microbubbles, which turns them into therapeutic warheads that trigger potent mechanical effects in the surrounding tissue. The use of nanoscale nanodroplets coupled with low-frequency ultrasound reduces the pressure threshold required for mechanical ultrasound surgery by an order of magnitude. In addition, their average diameter of 300 nm can overcome challenges associated with the size of microbubbles. Optimization experiments were performed to determine the ultrasound parameters for nanodroplet vaporization and the subsequent microbubble implosion processes. Optimal vaporization was obtained when transmitting a 2-cycle excitation pulse at a center frequency of 5 MHz and a peak negative pressure of 4.1 MPa (mechanical index = 1.8). Low-frequency insonation of the generated microbubbles at a center frequency of 850, 250 or 80 kHz caused enhanced contrast reduction at a center frequency of 80 kHz, compared with the other frequencies, while operating at the same mechanical index of 0.9. Nanodroplet-mediated insonation of ex vivo chicken liver samples generated mechanical damage. Low-frequency treatment at a mechanical index of 0.9 and a center frequency of 80 kHz induced the largest lesion area (average of 0.59 mm2) compared with 250- and 850-kHz treatments with the same mechanical index (average lesions areas of 0.29 and 0.19 mm2, respectively, p < 0.001). The two-step approach makes it possible to conduct both the vaporization and implosion stages at mechanical indices below 1.9, thus avoiding undesired mechanical damage. The findings indicate that coupled with low-frequency ultrasound, nanodroplets can be used for low-energy mechanical ultrasound surgery.
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Affiliation(s)
- Bar Glickstein
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Mika Levron
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Sarah Shitrit
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Ramona Aronovich
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Yi Feng
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Tali Ilovitsh
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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15
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Lin C, Chen YZ, Wu B, Yang MT, Liu CQ, Zhao Y. Advances and prospects of ultrasound targeted drug delivery systems using biomaterial-modified micro/nanobubbles for tumor therapy. Curr Med Chem 2022; 29:5062-5075. [PMID: 35362371 DOI: 10.2174/0929867329666220331110315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/18/2022] [Accepted: 02/01/2022] [Indexed: 11/22/2022]
Abstract
The incidence of malignant tumors is rising rapidly and tends to be in the younger, which has been one of the most important factors endangering the safety of human life. Ultrasound micro/nanobubbles, as a noninvasive and highly specific antitumor strategy, can reach and destroy tumor tissue through their effects of cavitation and acoustic perforation under the guidance of ultrasound. Meanwhile, micro/nanobubbles are now used as a novel drug carrier, releasing drugs at a target region, especially on the prospects of biomaterial-modified micro/nanobubbles as a dual modality for drug delivery and therapeutic monitoring. and successful evaluation of the sonoporation mechanism(s), ultrasound parameters, drug type and dose will need to be addressed before translating this technology for clinical use. Therefore, this paper collects the literature on the experimental and clinical studies of ultrasound biomaterial-modified micro/nanobubbles therapy in vitro and in vivo in recent years.
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Affiliation(s)
- Chen Lin
- Medical College of China three Gorges University;Yichang; China
| | - Ye-Zi Chen
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy,China Three Gorges University; Yichang; China
| | - Bo Wu
- Medical College of China three Gorges University;Yichang; China
| | - Meng-Ting Yang
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy,China Three Gorges University; Yichang; China
| | - Chao-Qi Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy,China Three Gorges University; Yichang; China
| | - Yun Zhao
- Medical College of China three Gorges University;Yichang; China
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16
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Jing B, Lindsey BD. Very Low Frequency Radial Modulation for Deep Penetration Contrast-Enhanced Ultrasound Imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2022; 48:530-545. [PMID: 34972572 DOI: 10.1016/j.ultrasmedbio.2021.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 11/16/2021] [Accepted: 11/21/2021] [Indexed: 06/14/2023]
Abstract
Contrast-enhanced ultrasound imaging allows vascular imaging in a variety of diseases. Radial modulation imaging is a contrast agent-specific imaging approach for improving microbubble detection at high imaging frequencies (≥7.5 MHz), with imaging depth limited to a few centimeters. To provide high-sensitivity contrast-enhanced ultrasound imaging at high penetration depths, a new radial modulation imaging strategy using a very low frequency (100 kHz) ultrasound modulation wave in combination with imaging pulses ≤5 MHz is proposed. Microbubbles driven at 100 kHz were imaged in 10 successive oscillation states by manipulating the pulse repetition frequency to unlock the frame rate from the number of oscillation states. Tissue background was suppressed using frequency domain radial modulation imaging (F-RMI) and singular value decomposition-based radial modulation imaging (S-RMI). One hundred-kilohertz modulation resulted in significantly higher microbubble signal magnitude (63-88 dB) at the modulation frequency relative to that without 100-kHz modulation (51-59 dB). F-RMI produced images with high contrast-to-tissue ratios (CTRs) of 15 to 22 dB in a stationary tissue phantom, while S-RMI further improved the CTR (19-26 dB). These CTR values were significantly higher than that of amplitude modulation pulse inversion images (11.9 dB). In the presence of tissue motion (1 and 10 mm/s), S-RMI produced high-contrast images with CTR up to 18 dB; however, F-RMI resulted in minimal contrast enhancement in the presence of tissue motion. Finally, in transcranial ultrasound imaging studies through a highly attenuating ex vivo cranial bone, CTR values with S-RMI were as high as 23 dB. The proposed technique demonstrates successful modulation of microbubble response at 100 kHz for the first time. The presented S-RMI low-frequency radial modulation imaging strategy represents the first demonstration of real-time (20 frames/s), high-penetration-depth radial modulation imaging for contrast-enhanced ultrasound imaging.
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Affiliation(s)
- Bowen Jing
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Brooks D Lindsey
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA; School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
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17
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Seo H, Huh H, Lee EH, Park J. Numerical Evaluation of the Effects of Transducer Displacement on Transcranial Focused Ultrasound in the Rat Brain. Brain Sci 2022; 12:216. [PMID: 35203979 PMCID: PMC8870101 DOI: 10.3390/brainsci12020216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/15/2022] [Accepted: 02/03/2022] [Indexed: 02/04/2023] Open
Abstract
Focused ultrasound is a promising therapeutic technique, as it involves the focusing of an ultrasonic beam with sufficient acoustic energy into a target brain region with high precision. Low-intensity ultrasound transmission by a single-element transducer is mostly established for neuromodulation applications and blood-brain barrier disruption for drug delivery. However, transducer positioning errors can occur without fine control over the sonication, which can affect repeatability and lead to reliability problems. The objective of this study was to determine whether the target brain region would be stable under small displacement (0.5 mm) of the transducer based on numerical simulations. Computed-tomography-derived three-dimensional models of a rat head were constructed to investigate the effects of transducer displacement in the caudate putamen (CP) and thalamus (TH). Using three different frequencies (1.1, 0.69, and 0.25 MHz), the transducer was displaced by 0.5 mm in each of the following six directions: superior, interior, anterior, posterior, left, and right. The maximum value of the intracranial pressure field was calculated, and the targeting errors were determined by the full-width-at-half-maximum (FWHM) overlap between the free water space (FWHMwater) and transcranial transmission (FWHMbase). When the transducer was positioned directly above the target region, a clear distinction between the target regions was observed, resulting in 88.3%, 81.5%, and 84.5% FWHMwater for the CP and 65.6%, 76.3%, and 64.4% FWHMwater for the TH at 1.1, 0.69, and 0.25 MHz, respectively. Small transducer displacements induced both enhancement and reduction of the peak pressure and targeting errors, compared with when the transducer was displaced in water. Small transducer displacement to the left resulted in the lowest stability, with 34.8% and 55.0% targeting accuracy (FWHMwater) at 1.1 and 0.69 MHz in the TH, respectively. In addition, the maximum pressure was reduced by up to 11% by the transducer displacement. This work provides the targeting errors induced by transducer displacements through a preclinical study and recommends that attention be paid to determining the initial sonication foci in the transverse plane in the cases of small animals.
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Affiliation(s)
- Hyeon Seo
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
| | - Hyungkyu Huh
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
| | - Eun-Hee Lee
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
| | - Juyoung Park
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Korea; (H.S.); (H.H.); (E.-H.L.)
- Department of High-Tech Medical Device, College of Future Industry, Gachon University, Seongnam-si 13120, Korea
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18
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Sujarittam K, Choi JJ. The relationship between bubble concentration and the acoustic emission energy of separate frequency bands. JASA EXPRESS LETTERS 2022; 2:022002. [PMID: 36154265 DOI: 10.1121/10.0009394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
This letter presents the relationship between bubble concentration and the energy ratio of low to high frequency bands of their acoustic emissions. Two sensors, placed perpendicular and concentric to a transmitter, captured the emissions from sonicated microbubbles. Emissions from different bubbles arrived at the perpendicular sensor with small time differences. Low frequencies with periods longer than the time differences interfered constructively, while higher frequencies interfered both constructively and destructively. The low-frequency (2nd-3rd harmonics) to high-frequency (7th-12th harmonics) energy ratio increased with the bubble concentration. The relationship was not observed with the concentric sensor, where the time differences were larger.
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Affiliation(s)
- Krit Sujarittam
- Department of Bioengineering, Imperial College London, 2 Imperial College Road, South Kensington, London, SW7 2AZ, United Kingdom ,
| | - James J Choi
- Department of Bioengineering, Imperial College London, 2 Imperial College Road, South Kensington, London, SW7 2AZ, United Kingdom ,
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Zhang N, Wang J, Foiret J, Dai Z, Ferrara KW. Synergies between therapeutic ultrasound, gene therapy and immunotherapy in cancer treatment. Adv Drug Deliv Rev 2021; 178:113906. [PMID: 34333075 PMCID: PMC8556319 DOI: 10.1016/j.addr.2021.113906] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/12/2021] [Accepted: 07/25/2021] [Indexed: 12/14/2022]
Abstract
Due to the ease of use and excellent safety profile, ultrasound is a promising technique for both diagnosis and site-specific therapy. Ultrasound-based techniques have been developed to enhance the pharmacokinetics and efficacy of therapeutic agents in cancer treatment. In particular, transfection with exogenous nucleic acids has the potential to stimulate an immune response in the tumor microenvironment. Ultrasound-mediated gene transfection is a growing field, and recent work has incorporated this technique into cancer immunotherapy. Compared with other gene transfection methods, ultrasound-mediated gene transfection has a unique opportunity to augment the intracellular uptake of nucleic acids while safely and stably modulating the expression of immunostimulatory cytokines. The development and commercialization of therapeutic ultrasound systems further enhance the potential translation. In this Review, we introduce the underlying mechanisms and ongoing preclinical studies of ultrasound-based techniques in gene transfection for cancer immunotherapy. Furthermore, we expand on aspects of therapeutic ultrasound that impact gene therapy and immunotherapy, including tumor debulking, enhancing cytokines and chemokines and altering nanoparticle pharmacokinetics as these effects of ultrasound cannot be fully dissected from targeted gene therapy. We finally explore the outlook for this rapidly developing field.
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Affiliation(s)
- Nisi Zhang
- Department of Radiology, Stanford University, Palo Alto, CA, USA; Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China
| | - James Wang
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Josquin Foiret
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Zhifei Dai
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China.
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Gümmer J, Schenke S, Denner F. Modelling Lipid-Coated Microbubbles in Focused Ultrasound Applications at Subresonance Frequencies. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:2958-2979. [PMID: 34344560 DOI: 10.1016/j.ultrasmedbio.2021.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/15/2021] [Accepted: 06/20/2021] [Indexed: 06/13/2023]
Abstract
We present a computational study of the behaviour of a lipid-coated SonoVue microbubble with initial radius 1 µm ≤ R0 ≤ 2 µm, excited at frequencies (200-1500 kHz) significantly below the linear resonance frequency and pressure amplitudes of up to 1500 kPa-an excitation regime used in many applications of focused ultrasound. The bubble dynamics are simulated using the Rayleigh-Plesset equation and the Gilmore equation, in conjunction with the Marmottant model for the lipid monolayer coating. Also, a new continuously differentiable variant of the Marmottant model is introduced. Below the onset of inertial cavitation, a linear regime is identified in which the maximum pressure at the bubble wall is linearly proportional to the excitation pressure amplitude and the mechanical index. This linear regime is bounded by the Blake pressure, and, in line with recent in vitro experiments, the onset of inertial cavitation is found to occur at an excitation pressure amplitude of approximately 130-190 kPa, depending on the initial bubble size. In the nonlinear regime the maximum pressure at the bubble wall is found to be readily predicted by the maximum bubble radius, and both the Rayleigh-Plesset and Gilmore equations are shown to predict the onset of sub- and ultraharmonic frequencies of the acoustic emissions compared with in vitro experiments. Neither the surface dilational viscosity of the lipid monolayer nor the compressibility of the liquid has a discernible influence on the quantities studied, but accounting for the lipid coating is critical for accurate prediction of the bubble behaviour. The Gilmore equation is shown to be valid for the bubbles and excitation regime considered, and the Rayleigh-Plesset equation also provides accurate qualitative predictions, even though it is outside its range of validity for many of the cases considered.
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Affiliation(s)
- Jonas Gümmer
- Chair of Mechanical Process Engineering, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany
| | - Sören Schenke
- Chair of Mechanical Process Engineering, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany
| | - Fabian Denner
- Chair of Mechanical Process Engineering, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany.
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21
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Blais S, Porée J, Ramos-Palacios G, Desmarais S, Perrot V, Sadikot A, Provost J. Equivalent time active cavitation imaging. Phys Med Biol 2021; 66. [PMID: 34320473 DOI: 10.1088/1361-6560/ac1877] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 07/28/2021] [Indexed: 11/12/2022]
Abstract
RATIONALE Despite the development of a large number of neurologically active drugs, brain diseases are difficult to treat due to the inability of many drugs to penetrate the blood-brain barrier. High-intensity focused ultrasound blood-brain barrier opening in a site-specific manner could significantly expand the spectrum of available drug treatments. However, without monitoring, brain damage and off target effects can occur during these treatments. While some methods can monitor inertial cavitation, temperature increase, or passively monitor cavitation events, to the best of our knowledge none of them can actively and spatiotemporally map the high intensity focused ultrasound pressure field during treatment. METHODS Here we detail the development of a novel ultrasound imaging modality called Equivalent Time Active Cavitation Imaging capable of characterizing the high-intensity focused ultrasound pressure field through stable cavitation events across the field of view with an ultrafast active imaging setup. This work introduces 1) a novel plane wave sequence whose transmit delays increase linearly with transmit events enabling the sampling of high-frequency cavitation events, and 2) an algorithm allowing the filtration of the microbubble signal for pressure field mapping. The pressure measurements with our modality were first carried out in vitro for hydrophone comparison and then in vivo during blood-brain barrier opening treatment in mice. RESULTS This study demonstrates the ability of our modality to spatiotemporally characterize a modulation pressure field with an active imaging setup. The resulting pressure field mapping reveals a good correlation with hydrophone measurements. Further proof is provided experimentally in vivo with promising results. CONCLUSION This proof of concept establishes the first steps towards a novel ultrasound modality for monitoring focused ultrasound blood-brain barrier opening, allowing new possibilities for a safe and precise monitoring method.
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Affiliation(s)
- Simon Blais
- Engineering Physics Department, Polytechnique Montréal, Montreal, Quebec, CANADA
| | - Jonathan Porée
- Engineering Physics Department, Polytechnique Montreal, Montreal, Quebec, CANADA
| | | | - Samuel Desmarais
- Engineering Physics Department, Montreal Polytechnic, Montreal, Quebec, CANADA
| | - Vincent Perrot
- Engineering Physics Department, Polytechnique Montréal, Montreal, Quebec, CANADA
| | - Abbas Sadikot
- Montreal Neurological Institute and Hospital, Montreal, Quebec, CANADA
| | - Jean Provost
- 1 Engineering Physics Department, Polytechnique Montreal, Montreal, Quebec, CANADA
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22
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Bismuth M, Katz S, Rosenblatt H, Twito M, Aronovich R, Ilovitsh T. Acoustically Detonated Microbubbles Coupled with Low Frequency Insonation: Multiparameter Evaluation of Low Energy Mechanical Ablation. Bioconjug Chem 2021; 33:1069-1079. [PMID: 34280311 PMCID: PMC9204695 DOI: 10.1021/acs.bioconjchem.1c00203] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
Noninvasive
ultrasound surgery can be achieved using focused ultrasound
to locally affect the targeted site without damaging intervening tissues.
Mechanical ablation and histotripsy use short and intense acoustic
pulses to destroy the tissue via a purely mechanical effect. Here,
we show that coupled with low-frequency excitation, targeted microbubbles
can serve as mechanical therapeutic warheads that trigger potent mechanical
effects in tumors using focused ultrasound. Upon low frequency excitation
(250 kHz and below), high amplitude microbubble oscillations occur
at substantially lower pressures as compared to higher MHz ultrasonic
frequencies. For example, inertial cavitation was initiated at a pressure
of 75 kPa for a center frequency of 80 kHz. Low frequency insonation
of targeted microbubbles was then used to achieve low energy tumor
cell fractionation at pressures below a mechanical index of 1.9, and
in accordance with the Food and Drug Administration guidelines. We
demonstrate these capabilities in vitro and in vivo. In cell cultures,
cell viability was reduced to 16% at a peak negative pressure of 800
kPa at the 250 kHz frequency (mechanical index of 1.6) and to 10%
at a peak negative pressure of 250 kPa at a frequency of 80 kHz (mechanical
index of 0.9). Following an intratumoral injection of targeted microbubbles
into tumor-bearing mice, and coupled with low frequency ultrasound
application, significant tumor debulking and cancer cell death was
observed. Our findings suggest that reducing the center frequency
enhances microbubble-mediated mechanical ablation; thus, this technology
provides a unique theranostic platform for safe low energy tumor fractionation,
while reducing off-target effects.
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Affiliation(s)
- Mike Bismuth
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sharon Katz
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.,The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Hagar Rosenblatt
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Maayan Twito
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ramona Aronovich
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tali Ilovitsh
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel.,The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
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23
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Karakatsani ME, Pouliopoulos AN, Liu M, Jambawalikar SR, Konofagou EE. Contrast-Free Detection of Focused Ultrasound-Induced Blood-Brain Barrier Opening Using Diffusion Tensor Imaging. IEEE Trans Biomed Eng 2021; 68:2499-2508. [PMID: 33360980 DOI: 10.1109/tbme.2020.3047575] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Focused ultrasound (FUS) has emerged as a non-invasive technique to locally and reversibly disrupt the blood-brain barrier (BBB). Here, we investigate the use of diffusion tensor imaging (DTI) as a means of detecting FUS-induced BBB opening at the absence of an MRI contrast agent. A non-human primate (NHP) was repeatedly treated with FUS and preformed circulating microbubbles to transiently disrupt the BBB (n = 4). T1- and diffusion-weighted MRI scans were acquired after the ultrasound treatment, with and without gadolinium-based contrast agent, respectively. Both scans were registered with a high-resolution T1-weighted scan of the NHP to investigate signal correlations. DTI detected an increase in fractional anisotropy from 0.21 ± 0.02 to 0.38 ± 0.03 (82.6 ± 5.2% change) within the targeted area one hour after BBB opening. Enhanced DTI contrast overlapped by 77.22 ± 9.2% with hyper-intense areas of gadolinium-enhanced T1-weighted scans, indicating diffusion anisotropy enhancement only within the BBB opening volume. Diffusion was highly anisotropic and unidirectional within the treated brain region, as indicated by the direction of the principal diffusion eigenvectors. Polar and azimuthal angle ranges decreased by 35.6% and 82.4%, respectively, following BBB opening. Evaluation of the detection methodology on a second NHP (n = 1) confirmed the across-animal feasibility of the technique. In conclusion, DTI may be used as a contrast-free MR imaging modality in lieu of contrast-enhanced T1 mapping for detecting BBB opening during focused-ultrasound treatment or evaluating BBB integrity in brain-related pathologies.
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24
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Anderson CD, Walton CB, Shohet RV. A Comparison of Focused and Unfocused Ultrasound for Microbubble-Mediated Gene Delivery. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:1785-1800. [PMID: 33812691 PMCID: PMC8169610 DOI: 10.1016/j.ultrasmedbio.2021.02.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 12/23/2020] [Accepted: 02/19/2021] [Indexed: 05/05/2023]
Abstract
We compared focused and unfocused ultrasound-targeted microbubble destruction (UTMD) for delivery of reporter plasmids to the liver and heart in mice. Optimal hepatic expression was seen with double-depth targeting at 5 and 13 mm in vivo, incorporating a low pulse repetition frequency and short pulse duration. Reporter expression was similar, but the transfection patterns were distinct, with intense foci of transfection using focused UTMD (F-UTMD). We then compared both approaches for cardiac delivery and found 10-fold stronger levels of reporter expression for F-UTMD and observed small areas of intense luciferase expression in the left ventricle. Non-linear contrast imaging of the liver before and after insonation also showed a substantially greater change in signal intensity for F-UTMD, suggesting distinct cavitation mechanisms for both approaches. Overall, similar levels of hepatic transgene expression were observed, but cardiac-directed F-UTMD was substantially more effective. Focused ultrasound presents a new frontier in UTMD-directed gene therapy.
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Affiliation(s)
- Cynthia D Anderson
- Department of Medicine, John A. Burns School of Medicine, Honolulu, Hawaii, USA
| | - Chad B Walton
- University of Hawaii at Manoa, Honolulu, Hawaii, USA
| | - Ralph V Shohet
- Department of Medicine, John A. Burns School of Medicine, Honolulu, Hawaii, USA.
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25
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Shende P, Trivedi R. Nanotheranostics in epilepsy: A perspective for multimodal diagnosis and strategic management. NANO SELECT 2021. [DOI: 10.1002/nano.202000141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Pravin Shende
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM'S NMIMS Vile Parle (W) Mumbai India
| | - Riddhi Trivedi
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM'S NMIMS Vile Parle (W) Mumbai India
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26
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Zhang N, Foiret J, Kheirolomoom A, Liu P, Feng Y, Tumbale S, Raie M, Wu B, Wang J, Fite BZ, Dai Z, Ferrara KW. Optimization of microbubble-based DNA vaccination with low-frequency ultrasound for enhanced cancer immunotherapy. ADVANCED THERAPEUTICS 2021; 4. [PMID: 34632048 DOI: 10.1002/adtp.202100033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Immunotherapy is an important cancer treatment strategy; nevertheless, the lack of robust immune cell infiltration in the tumor microenvironment remains a factor in limiting patient response rates. In vivo gene delivery protocols can amplify immune responses and sensitize tumors to immunotherapies, yet non-viral transfection methods often sacrifice transduction efficiency for improved safety tolerance. To improve transduction efficiency, we optimized a strategy employing low ultrasound transmission frequency-induced bubble oscillation to introduce plasmids into tumor cells. Differential centrifugation isolated size-specific microbubbles. The diameter of the small microbubble population was 1.27 ± 0.89 μm and that of larger population was 4.23 ± 2.27 μm. Upon in vitro insonation with the larger microbubble population, 29.7% of cancer cells were transfected with DNA plasmids, higher than that with smaller microbubbles (18.9%, P <0.05) or positive control treatments with a commercial transfection reagent (12%, P < 0.01). After 48 h, gene expression increased more than two-fold in tumors treated with large, as compared with small, microbubbles. Furthermore, the immune response, including tumor infiltration of CD8+ T cells and F4/80+ macrophages, was enhanced. We believe that this safe and efficacious method can improve preclinical procedures and outcomes for DNA vaccines in cancer immunotherapy in the future.
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Affiliation(s)
- Nisi Zhang
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Josquin Foiret
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | | | - Pei Liu
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Yi Feng
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Spencer Tumbale
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Marina Raie
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Bo Wu
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - James Wang
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Brett Z Fite
- Department of Radiology, Stanford University, Palo Alto, CA, USA
| | - Zhifei Dai
- Department of Engineering, Peking University, Beijing, China
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27
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Harnessing ultrasound-stimulated phase change contrast agents to improve antibiotic efficacy against methicillin-resistant Staphylococcus aureus biofilms. Biofilm 2021; 3:100049. [PMID: 34124645 PMCID: PMC8173270 DOI: 10.1016/j.bioflm.2021.100049] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/17/2022] Open
Abstract
Bacterial biofilms, often associated with chronic infections, respond poorly to antibiotic therapy and frequently require surgical intervention. Biofilms harbor persister cells, metabolically indolent cells, which are tolerant to most conventional antibiotics. In addition, the biofilm matrix can act as a physical barrier, impeding diffusion of antibiotics. Novel therapeutic approaches frequently improve biofilm killing, but usually fail to achieve eradication. Failure to eradicate the biofilm leads to chronic and relapsing infection, is associated with major financial healthcare costs and significant morbidity and mortality. We address this problem with a two-pronged strategy using 1) antibiotics that target persister cells and 2) ultrasound-stimulated phase-change contrast agents (US-PCCA), which improve antibiotic penetration. We previously demonstrated that rhamnolipids, produced by Pseudomonas aeruginosa, could induce aminoglycoside uptake in gram-positive organisms, leading to persister cell death. We have also shown that US-PCCA can transiently disrupt biological barriers to improve penetration of therapeutic macromolecules. We hypothesized that combining antibiotics which target persister cells with US-PCCA to improve drug penetration could improve treatment of methicillin resistant S. aureus (MRSA) biofilms. Aminoglycosides alone or in combination with US-PCCA displayed limited efficacy against MRSA biofilms. In contrast, the anti-persister combination of rhamnolipids and aminoglycosides combined with US-PCCA dramatically improved biofilm killing. This novel treatment strategy has the potential for rapid clinical translation as the PCCA formulation is a variant of FDA-approved ultrasound contrast agents that are already in clinical practice and the low-pressure ultrasound settings used in our study can be achieved with existing ultrasound hardware at pressures below the FDA set limits for diagnostic imaging.
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28
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Vince O, Peeters S, Johanssen VA, Gray M, Smart S, Sibson NR, Stride E. Microbubbles Containing Lysolipid Enhance Ultrasound-Mediated Blood-Brain Barrier Breakdown In Vivo. Adv Healthc Mater 2021; 10:e2001343. [PMID: 33191662 DOI: 10.1002/adhm.202001343] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/09/2020] [Indexed: 12/13/2022]
Abstract
Ultrasound and microbubbles (MBs) offer a noninvasive method of temporarily enhancing blood-brain barrier (BBB) permeability to therapeutics. To reduce off-target effects, it is desirable to minimize the ultrasound pressures required. It has been shown that a new formulation of MBs containing lysolipids (Lyso-MBs) can increase the cellular uptake of a model drug in vitro. The aim of this study is to investigate whether Lyso-MBs can also enhance BBB permeability in vivo. Female BALB/c mice are injected with either Lyso-MBs or control MBs and gadolinium-DTPA (Gd-DTPA) and exposed to ultrasound (500 kHz, 1 Hz pulse repetition frequency, 1 ms pulse length, peak-negative pressures 160-480 kPa) for 2 min. BBB permeabilization is measured via magnetic resonance imaging (7.0 T) of Gd-DTPA extravasation and subsequent histological examination of brain tissue to assess serum immunoglobulin G (IgG) extravasation (n = 8 per group). An approximately twofold enhancement in BBB permeability is produced by the Lyso-MBs at the highest ultrasound pressure compared with the control. These findings indicate that modifying the composition of phospholipid-shelled MBs has the potential to improve the efficiency of BBB opening, without increasing the ultrasound pressure amplitude required. This is particularly relevant for delivery of therapeutics deep within the brain.
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Affiliation(s)
- Oliver Vince
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sarah Peeters
- Medical Research Council Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Vanessa A Johanssen
- Medical Research Council Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Michael Gray
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sean Smart
- Medical Research Council Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Nicola R Sibson
- Medical Research Council Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Eleanor Stride
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, OX3 7DQ, UK
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29
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Choi SW, Gerhardson TI, Duclos SE, Surowiec RK, Scheven UM, Galban S, Lee FT, Greve JM, Balter JM, Hall TL, Xu Z. Stereotactic Transcranial Focused Ultrasound Targeting System for Murine Brain Models. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:154-163. [PMID: 32746229 PMCID: PMC7814337 DOI: 10.1109/tuffc.2020.3012303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An inexpensive, accurate focused ultrasound stereotactic targeting method guided by pretreatment magnetic resonance imaging (MRI) images for murine brain models is presented. An uncertainty of each sub-component of the stereotactic system was analyzed. The entire system was calibrated using clot phantoms. The targeting accuracy of the system was demonstrated with an in vivo mouse glioblastoma (GBM) model. The accuracy was quantified by the absolute distance difference between the prescribed and ablated points visible on the pre treatment and posttreatment MR images, respectively. A precalibration phantom study ( N = 6 ) resulted in an error of 0.32 ± 0.31, 0.72 ± 0.16, and 1.06 ± 0.38 mm in axial, lateral, and elevational axes, respectively. A postcalibration phantom study ( N = 8 ) demonstrated a residual error of 0.09 ± 0.01, 0.15 ± 0.09, and 0.47 ± 0.18 mm in axial, lateral, and elevational axes, respectively. The calibrated system showed significantly reduced ( ) error of 0.20 ± 0.21, 0.34 ± 0.24, and 0.28 ± 0.21 mm in axial, lateral, and elevational axes, respectively, in the in vivo GBM tumor-bearing mice ( N = 10 ).
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30
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Recent Advances on Ultrasound Contrast Agents for Blood-Brain Barrier Opening with Focused Ultrasound. Pharmaceutics 2020; 12:pharmaceutics12111125. [PMID: 33233374 PMCID: PMC7700476 DOI: 10.3390/pharmaceutics12111125] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
The blood-brain barrier is the primary obstacle to efficient intracerebral drug delivery. Focused ultrasound, in conjunction with microbubbles, is a targeted and non-invasive way to disrupt the blood-brain barrier. Many commercially available ultrasound contrast agents and agents specifically designed for therapeutic purposes have been investigated in ultrasound-mediated blood-brain barrier opening studies. The new generation of sono-sensitive agents, such as liquid-core droplets, can also potentially disrupt the blood-brain barrier after their ultrasound-induced vaporization. In this review, we describe the different compositions of agents used for ultrasound-mediated blood-brain barrier opening in recent studies, and we discuss the challenges of the past five years related to the optimal formulation of agents.
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31
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Sujarittam K, Choi JJ. Angular dependence of the acoustic signal of a microbubble cloud. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 148:2958. [PMID: 33261381 DOI: 10.1121/10.0002490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 10/22/2020] [Indexed: 06/12/2023]
Abstract
Microbubble-mediated ultrasound therapies have a common need for methods that can noninvasively monitor the treatment. One approach is to use the bubbles' acoustic emissions as feedback to the operator or a control unit. Current methods interpret the emissions' frequency content to infer the microbubble activities and predict therapeutic outcomes. However, different studies placed their sensors at different angles relative to the emitter and bubble cloud. Here, it is evaluated whether such angles influence the captured emissions such as the frequency content. In computer simulations, 128 coupled bubbles were sonicated with a 0.5-MHz, 0.35-MPa pulse, and the acoustic emissions generated by the bubbles were captured with two sensors placed at different angles. The simulation was replicated in experiments using a microbubble-filled gel channel (0.5-MHz, 0.19-0.75-MPa pulses). A hydrophone captured the emissions at two different angles. In both the simulation and the experiments, one angle captured periodic time-domain signals, which had high contributions from the first three harmonics. In contrast, the other angle captured visually aperiodic time-domain features, which had much higher harmonic and broadband content. Thus, by placing acoustic sensors at different positions, substantially different acoustic emissions were captured, potentially leading to very different conclusions about the treatment outcome.
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Affiliation(s)
- Krit Sujarittam
- Department of Bioengineering, Imperial College London, 2 Imperial College Road, South Kensington, London, SW7 2AZ, United Kingdom
| | - James J Choi
- Department of Bioengineering, Imperial College London, 2 Imperial College Road, South Kensington, London, SW7 2AZ, United Kingdom
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32
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Ilovitsh T, Feng Y, Foiret J, Kheirolomoom A, Zhang H, Ingham ES, Ilovitsh A, Tumbale SK, Fite BZ, Wu B, Raie MN, Zhang N, Kare AJ, Chavez M, Qi LS, Pelled G, Gazit D, Vermesh O, Steinberg I, Gambhir SS, Ferrara KW. Low-frequency ultrasound-mediated cytokine transfection enhances T cell recruitment at local and distant tumor sites. Proc Natl Acad Sci U S A 2020; 117:12674-12685. [PMID: 32430322 PMCID: PMC7293655 DOI: 10.1073/pnas.1914906117] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Robust cytotoxic T cell infiltration has proven to be difficult to achieve in solid tumors. We set out to develop a flexible protocol to efficiently transfect tumor and stromal cells to produce immune-activating cytokines, and thus enhance T cell infiltration while debulking tumor mass. By combining ultrasound with tumor-targeted microbubbles, membrane pores are created and facilitate a controllable and local transfection. Here, we applied a substantially lower transmission frequency (250 kHz) than applied previously. The resulting microbubble oscillation was significantly enhanced, reaching an effective expansion ratio of 35 for a peak negative pressure of 500 kPa in vitro. Combining low-frequency ultrasound with tumor-targeted microbubbles and a DNA plasmid construct, 20% of tumor cells remained viable, and ∼20% of these remaining cells were transfected with a reporter gene both in vitro and in vivo. The majority of cells transfected in vivo were mucin 1+/CD45- tumor cells. Tumor and stromal cells were then transfected with plasmid DNA encoding IFN-β, producing 150 pg/106 cells in vitro, a 150-fold increase compared to no-ultrasound or no-plasmid controls and a 50-fold increase compared to treatment with targeted microbubbles and ultrasound (without IFN-β). This enhancement in secretion exceeds previously reported fourfold to fivefold increases with other in vitro treatments. Combined with intraperitoneal administration of checkpoint inhibition, a single application of IFN-β plasmid transfection reduced tumor growth in vivo and recruited efficacious immune cells at both the local and distant tumor sites.
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Affiliation(s)
- Tali Ilovitsh
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
- Department of Biomedical Engineering, University of California, Davis, CA 95616
| | - Yi Feng
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
- Department of Biomedical Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Josquin Foiret
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Azadeh Kheirolomoom
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
- Department of Biomedical Engineering, University of California, Davis, CA 95616
| | - Hua Zhang
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
- Department of Biomedical Engineering, University of California, Davis, CA 95616
| | - Elizabeth S Ingham
- Department of Biomedical Engineering, University of California, Davis, CA 95616
| | - Asaf Ilovitsh
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
- Department of Biomedical Engineering, University of California, Davis, CA 95616
| | - Spencer K Tumbale
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Brett Z Fite
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Bo Wu
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Marina N Raie
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Nisi Zhang
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Aris J Kare
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Michael Chavez
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Lei S Qi
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Gadi Pelled
- Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Dan Gazit
- Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048
| | - Ophir Vermesh
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Idan Steinberg
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Sanjiv S Gambhir
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305
- Department of Radiology, Stanford University, Stanford, CA 94305
| | - Katherine W Ferrara
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305;
- Department of Radiology, Stanford University, Stanford, CA 94305
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33
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Escoffre JM, Campomanes P, Tarek M, Bouakaz A. New insights on the role of ROS in the mechanisms of sonoporation-mediated gene delivery. ULTRASONICS SONOCHEMISTRY 2020; 64:104998. [PMID: 32062534 DOI: 10.1016/j.ultsonch.2020.104998] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 01/13/2020] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
Reactive oxygen species (ROS) are hypothesized to play a role in the sonoporation mechanisms. Nevertheless, the acoustical phenomenon behind the ROS production as well as the exact mechanisms of ROS action involved in the increased cell membrane permeability are still not fully understood. Therefore, we investigated the key processes occurring at the molecular level in and around microbubbles subjected to ultrasound using computational chemistry methods. To confirm the molecular simulation predictions, we measured the ROS production by exposing SonoVue® microbubbles (MBs) to ultrasound using biological assays. To investigate the role of ROS in cell membrane permeabilization, cells were subjected to ultrasound in presence of MBs and plasmid encoding reporter gene, and the transfection level was assessed using flow cytometry. The molecular simulations showed that under sonoporation conditions, ROS can form inside the MBs. These radicals could easily diffuse through the MB shell toward the surrounding aqueous phase and participate in the permeabilization of nearby cell membranes. Experimental data confirmed that MBs favor spontaneous formation of a host of free radicals where HO was the main ROS species after US exposure. The presence of ROS scavengers/inhibitors during the sonoporation process decreased both the production of ROS and the subsequent transfection level without significant loss of cell viability. In conclusion, the exposure of MBs to ultrasound might be the origin of chemical effects, which play a role in the cell membrane permeabilization and in the in vitro gene delivery when generated in its proximity.
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Affiliation(s)
| | - Pablo Campomanes
- Laboratoire de Physique et Chimie Théoriques, UMR 7019, Université de Lorraine, CNRS, Nancy F-54000, France
| | - Mounir Tarek
- Laboratoire de Physique et Chimie Théoriques, UMR 7019, Université de Lorraine, CNRS, Nancy F-54000, France.
| | - Ayache Bouakaz
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.
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34
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Pouliopoulos AN, Jimenez DA, Frank A, Robertson A, Zhang L, Kline-Schoder AR, Bhaskar V, Harpale M, Caso E, Papapanou N, Anderson R, Li R, Konofagou EE. Temporal stability of lipid-shelled microbubbles during acoustically-mediated blood-brain barrier opening. FRONTIERS IN PHYSICS 2020; 8:137. [PMID: 32457896 PMCID: PMC7250395 DOI: 10.3389/fphy.2020.00137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Non-invasive blood-brain barrier (BBB) opening using focused ultrasound (FUS) is being tested as a means to locally deliver drugs into the brain. Such FUS therapies require injection of preformed microbubbles, currently used as contrast agents in ultrasound imaging. Although their behavior during exposure to imaging sequences has been well described, our understanding of microbubble stability within a therapeutic field is still not complete. Here, we study the temporal stability of lipid-shelled microbubbles during therapeutic FUS exposure in two timescales: the short time scale (i.e., μs of low-frequency ultrasound exposure) and the long time scale (i.e., days post-activation). We first simulated the microbubble response to low-frequency sonication, and found a strong correlation between viscosity and fragmentation pressure. Activated microbubbles had a concentration decay constant of 0.02 d-1 but maintained a quasi-stable size distribution for up to 3 weeks (< 10% variation). Microbubbles flowing through a 4-mm vessel within a tissue-mimicking phantom (5% gelatin) were exposed to therapeutic pulses (fc: 0.5 MHz, peak-negative pressure: 300 kPa, pulse length: 1 ms, pulse repetition frequency: 1 Hz, n=10). We recorded and analyzed their acoustic emissions, focusing on emitted energy and its temporal evolution, alongside the frequency content. Measurements were repeated with concentration-matched samples (107 microbubbles/ml) on day 0, 7, 14, and 21 after activation. Temporal stability decreased while inertial cavitation response increased with storage time both in vitro and in vivo, possibly due to changes in the shell lipid content. Using the same parameters and timepoints, we performed BBB opening in a mouse model (n=3). BBB opening volume measured through T1-weighted contrast-enhanced MRI was equal to 19.1 ± 7.1 mm3, 21.8 ± 14 mm3, 29.3 ± 2.5 mm3, and 38 ± 20.1 mm3 on day 0, 7, 14, and 21, respectively, showing no significant difference over time (p-value: 0.49). Contrast enhancement was 24.9 ± 1.7 %, 23.7 ± 11.7 %, 28.9 ± 5.3 %, and 35 ± 13.4 %, respectively (p-value: 0.63). In conclusion, the in-house made microbubbles studied here maintain their capacity to produce similar therapeutic effects over a period of 3 weeks after activation, as long as the natural concentration decay is accounted for. Future work should focus on stability of commercially available microbubbles and tailoring microbubble shell properties towards therapeutic applications.
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Affiliation(s)
| | - Daniella A. Jimenez
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Alexander Frank
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Alexander Robertson
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Lin Zhang
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Alina R. Kline-Schoder
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Vividha Bhaskar
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Mitra Harpale
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Elizabeth Caso
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Nicholas Papapanou
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Rachel Anderson
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Rachel Li
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
| | - Elisa E. Konofagou
- Department of Biomedical Engineering, Columbia University, New York City, New York 10032, USA
- Department of Radiology, Columbia University, New York City, New York 10032, USA
- Correspondence: Elisa E. Konofagou 351 Engineering Terrace, 1210 Amsterdam Avenue Mail Code: 8904, New York, NY, USA 10027 Phone: 212-342-0863, 212-854-9661
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Pouliopoulos AN, Wu SY, Burgess MT, Karakatsani ME, Kamimura HAS, Konofagou EE. A Clinical System for Non-invasive Blood-Brain Barrier Opening Using a Neuronavigation-Guided Single-Element Focused Ultrasound Transducer. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:73-89. [PMID: 31668690 PMCID: PMC6879801 DOI: 10.1016/j.ultrasmedbio.2019.09.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 05/07/2023]
Abstract
Focused ultrasound (FUS)-mediated blood-brain barrier (BBB) opening is currently being investigated in clinical trials. Here, we describe a portable clinical system with a therapeutic transducer suitable for humans, which eliminates the need for in-line magnetic resonance imaging (MRI) guidance. A neuronavigation-guided 0.25-MHz single-element FUS transducer was developed for non-invasive clinical BBB opening. Numerical simulations and experiments were performed to determine the characteristics of the FUS beam within a human skull. We also validated the feasibility of BBB opening obtained with this system in two non-human primates using U.S. Food and Drug Administration (FDA)-approved treatment parameters. Ultrasound propagation through a human skull fragment caused 44.4 ± 1% pressure attenuation at a normal incidence angle, while the focal size decreased by 3.3 ± 1.4% and 3.9 ± 1.8% along the lateral and axial dimension, respectively. Measured lateral and axial shifts were 0.5 ± 0.4 mm and 2.1 ± 1.1 mm, while simulated shifts were 0.1 ± 0.2 mm and 6.1 ± 2.4 mm, respectively. A 1.5-MHz passive cavitation detector transcranially detected cavitation signals of Definity microbubbles flowing through a vessel-mimicking phantom. T1-weighted MRI confirmed a 153 ± 5.5 mm3 BBB opening in two non-human primates at a mechanical index of 0.4, using Definity microbubbles at the FDA-approved dose for imaging applications, without edema or hemorrhage. In conclusion, we developed a portable system for non-invasive BBB opening in humans, which can be achieved at clinically relevant ultrasound exposures without the need for in-line MRI guidance. The proposed FUS system may accelerate the adoption of non-invasive FUS-mediated therapies due to its fast application, low cost and portability.
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Affiliation(s)
| | - Shih-Ying Wu
- Department of Biomedical Engineering, Columbia University, New York City, New York, USA
| | - Mark T Burgess
- Department of Biomedical Engineering, Columbia University, New York City, New York, USA
| | | | - Hermes A S Kamimura
- Department of Biomedical Engineering, Columbia University, New York City, New York, USA
| | - Elisa E Konofagou
- Department of Biomedical Engineering, Columbia University, New York City, New York, USA; Department of Radiology, Columbia University, New York City, New York, USA.
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36
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Cleve S, Inserra C, Prentice P. Contrast Agent Microbubble Jetting during Initial Interaction with 200-kHz Focused Ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:3075-3080. [PMID: 31477370 PMCID: PMC6863384 DOI: 10.1016/j.ultrasmedbio.2019.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 05/22/2023]
Abstract
The initial response of microbubbles flowing through a 500-μm polycarbonate capillary to a burst of 200-kHz focused ultrasound, at peak-negative pressure amplitudes from 0.7-1.5 MPa, was investigated with dual-perspective high-speed imaging. Directed jetting through the acoustic focus is demonstrated according to the pressure gradients acting across the cavitating microbubbles. At lower amplitudes, repeated microbubble-jetting is accompanied by sudden, intermittent translation. At higher amplitudes a rebound jet also forms, before disintegration into a cavitation cloud.
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Affiliation(s)
- Sarah Cleve
- Université Lyon, École Centrale de Lyon, INSA de Lyon, CNRS, LMFA UMR 5509, Écully, France
| | - Claude Inserra
- Université Lyon 1, Centre Léon Bérard, INSERM, LabTAU, Lyon, France
| | - Paul Prentice
- CavLab, Centre for Medical and Industrial Ultrasonics, University of Glasgow, Glasgow, United Kingdom.
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37
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Zhong Q, Yoon BC, Aryal M, Wang JB, Ilovitsh T, Baikoghli MA, Hosseini-Nassab N, Karthik A, Cheng RH, Ferrara KW, Airan RD. Polymeric perfluorocarbon nanoemulsions are ultrasound-activated wireless drug infusion catheters. Biomaterials 2019; 206:73-86. [PMID: 30953907 DOI: 10.1016/j.biomaterials.2019.03.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/11/2019] [Accepted: 03/15/2019] [Indexed: 01/04/2023]
Abstract
Catheter-based intra-arterial drug therapies have proven effective for a range of oncologic, neurologic, and cardiovascular applications. However, these procedures are limited by their invasiveness and relatively broad drug spatial distribution. The ideal technique for local pharmacotherapy would be noninvasive and would flexibly deliver a given drug to any region of the body with high spatial and temporal precision. Combining polymeric perfluorocarbon nanoemulsions with existent clinical focused ultrasound systems could in principle meet these needs, but it has not been clear whether these nanoparticles could provide the necessary drug loading, stability, and generalizability across a range of drugs, beyond a few niche applications. Here, we develop polymeric perfluorocarbon nanoemulsions into a generalized platform for ultrasound-targeted delivery of hydrophobic drugs with high potential for clinical translation. We demonstrate that a wide variety of drugs may be effectively uncaged with ultrasound using these nanoparticles, with drug loading increasing with hydrophobicity. We also set the stage for clinical translation by delineating production protocols that are scalable and yield sterile, stable, and optimized ultrasound-activated drug-loaded nanoemulsions. Finally, we exhibit a new potential application of these nanoemulsions for local control of vascular tone. This work establishes the power of polymeric perfluorocarbon nanoemulsions as a clinically-translatable platform for efficacious, noninvasive, and localized ultrasonic drug uncaging for myriad targets in the brain and body.
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Affiliation(s)
- Q Zhong
- Department of Radiology, Stanford University, Stanford, CA 94305, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - B C Yoon
- Department of Radiology, Stanford University, Stanford, CA 94305, USA; Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - M Aryal
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - J B Wang
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - T Ilovitsh
- Department of Radiology, Stanford University, Stanford, CA 94305, USA; Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - M A Baikoghli
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - N Hosseini-Nassab
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - A Karthik
- Department of Radiology, Stanford University, Stanford, CA 94305, USA
| | - R H Cheng
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - K W Ferrara
- Department of Radiology, Stanford University, Stanford, CA 94305, USA; Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - R D Airan
- Department of Radiology, Stanford University, Stanford, CA 94305, USA.
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