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Yao L, Luo T, Yang G, Yin J, Li H, Liu Z. An Experimental Study: Treatment of Subcutaneous C6 Glioma in Rats Using Acoustic Droplet Vaporization. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2023; 42:1951-1963. [PMID: 36916667 DOI: 10.1002/jum.16212] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 02/01/2023] [Accepted: 02/19/2023] [Indexed: 06/18/2023]
Abstract
OBJECTIVE The objective of this study was to investigate the treatment effects of acoustic droplet vaporization (ADV) on tumors. METHODS Experiments were conducted on subcutaneous C6 glioma implanted in 37 rats. Twenty-five rats were divided into five groups treated by ultrasound (US) + dodecafluoropentane (DDFP), US + microbubble (MB), US, DDFP, or saline, respectively. ADV was performed using DDFP droplets (2-5 μm) triggered by non-focused pulsed ultrasound. Macroscopic and histological changes of the tumor were compared with investigation of the tumor ablation effect of ADV. Tumor temperature was measured before and immediately after treatment to explore temperature changes. Furthermore, another 12 rats with bilateral tumors were divided into two groups. Six animals received ADV treatment on unilateral tumor, while another six received saline injection on unilateral tumor. The tumor blood perfusion, tumor volume and related immune response were measured. RESULTS The tumors treated by ADV were partially damaged without significant temperature rise. For the animals with bilateral tumors, the tumor blood perfusion around the damaged area on the side receiving ADV still existed. Additionally, the bilateral tumors of animals treated with ADV were smaller than those of animals treated with saline, along with stronger immune response and more tumor cell apoptosis in tumors on both sides. CONCLUSION The study demonstrated that ADV treatment could damage subcutaneous glioma in rats by mechanical effect and enhance systemic immune response to furtherly inhibit the tumor growth.
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Affiliation(s)
- Lei Yao
- Department of Ultrasound, The Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Tingting Luo
- Department of Ultrasound, The Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Guoliang Yang
- Department of Ultrasound, The Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Jiabei Yin
- Department of Ultrasound, The Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Hui Li
- Department of Ultrasound, The Second Affiliated Hospital of Army Medical University, Chongqing, China
| | - Zheng Liu
- Department of Ultrasound, The Second Affiliated Hospital of Army Medical University, Chongqing, China
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Xin Y, Zhang A, Xu LX, Fowlkes JB. Numerical Study of Bubble Cloud and Thermal Lesion Evolution During Acoustic Droplet Vaporization Enhanced HIFU Treatment. J Biomech Eng 2022; 144:1119457. [PMID: 34505142 DOI: 10.1115/1.4052374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Indexed: 11/08/2022]
Abstract
Acoustic droplet vaporization (ADV) has been proven to enhance high intensity focused ultrasound (HIFU) thermal ablation of tumor. It has also been demonstrated that triggering droplets before HIFU exposure could be a potential way to control both the size and the shape of the thermal lesion. In this paper, a numerical model is proposed to predict the thermal lesion created in ADV enhanced HIFU treatment. Bubble oscillation was coupled into a viscoelastic medium in the model to more closely represent real applications in tissues. Several physical processes caused by continuous wave ultrasound and elevated temperature during the HIFU exposure were considered, including rectified diffusion, gas solubility variation with temperature in the medium, and boiling. Four droplet concentrations spanning two orders of magnitude were calculated. The bubble cloud formed from triggering of the droplets by the pulse wave ultrasound, along with the evolution of the shape and location of the bubble cloud and thermal lesion during the following continuous wave exposure was obtained. The increase of bubble void fraction caused by continuous wave exposure was found to be consistent with the experimental observation. With the increase of droplet concentration, the predicted bubble cloud shapes vary from tadpole to triangular and double triangular, while the thermal lesions move toward the transducer. The results show that the assumptions used in this model increased the accuracy of the results. This model may be used for parametrical study of ADV enhanced HIFU treatment and be further used for treatment planning and optimization in the future.
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Affiliation(s)
- Ying Xin
- School of Biomedical Engineering, Shanghai Jiao Tong University, 400 Med-X Research Institute, 1954 Huashan Road, Shanghai 200030, China
| | - Aili Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, 400 Med-X Research Institute, 1954 Huashan Road, Shanghai 200030, China
| | - Lisa X Xu
- School of Biomedical Engineering, Shanghai Jiao Tong University, 400 Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - J Brian Fowlkes
- Department of Radiology, University of Michigan Health System, 3226C, Medical Sciences Building I, 1301 Catherine Street, Ann Arbor, MI 48109
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Investigation of the different parameters contributing to bubble sticking inside physiological bifurcations. Med Biol Eng Comput 2022; 60:599-618. [PMID: 35029813 DOI: 10.1007/s11517-021-02485-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 12/04/2021] [Indexed: 10/19/2022]
Abstract
Gas embolotherapy (GE) is a developing medical method which can be utilized either as an autonomous therapeutic method to treat vascularized solid tumors, or it can be combined with other medical procedures-such as high-intensity focused ultrasound-to improve their efficiency. This paper is dedicated to investigating the different parameters which influence bubble lodging inside human vasculature via 2D-modeling of bubble dynamics in arteries' and arterioles' bifurcations which are potential sticking positions. Values used in the simulations are in accordance with the non-dimensional physiological numbers. It is found out that inlet pressure plays a decisive role in bubble lodging; the lower the value, the higher the possibility of bubble sticking. On the other hand, gravity has a counteracting effect on bubble lodging in arteries, but not on arterioles. The initial length of the bubble is not a determining factor in sticking behavior, even though it affects the flow rate behavior. Surface tension, another critical factor, has a semi-linear impact on bubble resisting power; lowering the surface tension will reduce bubble resistance to the flow, diminishing the possibility of bubble lodging. Finally, it is shown that lower values for the static contact angle impose higher resistance to the flow.
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Durham PG, Dayton PA. Applications of sub-micron low-boiling point phase change contrast agents for ultrasound imaging and therapy. Curr Opin Colloid Interface Sci 2021. [DOI: 10.1016/j.cocis.2021.101498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ho YJ, Huang CC, Fan CH, Liu HL, Yeh CK. Ultrasonic technologies in imaging and drug delivery. Cell Mol Life Sci 2021; 78:6119-6141. [PMID: 34297166 PMCID: PMC11072106 DOI: 10.1007/s00018-021-03904-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 07/13/2021] [Accepted: 07/19/2021] [Indexed: 12/14/2022]
Abstract
Ultrasonic technologies show great promise for diagnostic imaging and drug delivery in theranostic applications. The development of functional and molecular ultrasound imaging is based on the technical breakthrough of high frame-rate ultrasound. The evolution of shear wave elastography, high-frequency ultrasound imaging, ultrasound contrast imaging, and super-resolution blood flow imaging are described in this review. Recently, the therapeutic potential of the interaction of ultrasound with microbubble cavitation or droplet vaporization has become recognized. Microbubbles and phase-change droplets not only provide effective contrast media, but also show great therapeutic potential. Interaction with ultrasound induces unique and distinguishable biophysical features in microbubbles and droplets that promote drug loading and delivery. In particular, this approach demonstrates potential for central nervous system applications. Here, we systemically review the technological developments of theranostic ultrasound including novel ultrasound imaging techniques, the synergetic use of ultrasound with microbubbles and droplets, and microbubble/droplet drug-loading strategies for anticancer applications and disease modulation. These advancements have transformed ultrasound from a purely diagnostic utility into a promising theranostic tool.
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Affiliation(s)
- Yi-Ju Ho
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Chih-Chung Huang
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
- Medical Device Innovation Center, National Cheng Kung University, Tainan, Taiwan
| | - Ching-Hsiang Fan
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
- Medical Device Innovation Center, National Cheng Kung University, Tainan, Taiwan
| | - Hao-Li Liu
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan.
| | - Chih-Kuang Yeh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
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Abstract
An air embolism is induced by intravascular bubbles that block the blood flow in vessels, which causes a high risk of pulmonary hypertension and myocardial and cerebral infarction. However, it is still unclear how a moving bubble is stopped in the blood flow to form an air embolism in small vessels. In this work, microfluidic experiments, in vivo and in vitro, are performed in small vessels, where bubbles are seen to deform and stop gradually in the flow. A clot is always found to originate at the tail of a moving bubble, which is attributed to the special flow field around the bubble. As the clot grows, it breaks the lubrication film between the bubble and the channel wall; thus, the friction force is increased to stop the bubble. This study illustrates the stopping process of elongated bubbles in small vessels and brings insight into the formation of air embolism.
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Gao B, Xu J, Zhou J, Zhang H, Yang R, Wang H, Huang J, Yan F, Luo Y. Multifunctional pathology-mapping theranostic nanoplatforms for US/MR imaging and ultrasound therapy of atherosclerosis. NANOSCALE 2021; 13:8623-8638. [PMID: 33929480 DOI: 10.1039/d1nr01096d] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Atherosclerotic thrombosis is the leading cause of most life-threatening cardiovascular diseases (CVDs), particularly as a result of rupture or erosion of vulnerable plaques. Rupture or erosion-prone plaques are quite different in cellular composition and immunopathology, requiring different treatment strategies. The current imaging technology cannot distinguish the types of vulnerable plaques, and thus empirical treatment is still applied to all without a tailored and precise treatment. Herein, we propose a novel strategy called "Multifunctional Pathology-mapping Theranostic Nanoplatform (MPmTN)" for the tailored treatment of plaques based on the pathological classification. MPmTNs are made up of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), containing contrast imaging materials Fe3O4 and perfluoropentane (PFP), and coated with specific plaque-targeted peptides PP1 and cyclic RGD. The PFP encapsulated inside the MPmTN can undergo a phase change from nanodroplets to gas microbubbles under therapeutic ultrasound (TUS) exposure. The acoustic and biological effects induced by TUS and disruption of microbubbles may further promote therapeutic effects. Hypothetically, MPmTN NPs can target the rupture-prone plaque via the binding of PP1 to class A scavenger receptors (SR-A) on macrophages, induce the apoptosis due to TUS exposure and thus reduce the chronic soakage of inflammatory cells. The MPmTN NPs can also target the erosion-prone plaque through the binding of cRGD to glycoprotein (GP) IIb/IIIa on activated platelets and promote platelet disaggregation under TUS exposure. Therefore, MPmTNs may work as a multifunctional pathology-mapping therapeutic agent. Our in vitro results show that the MPmTN with PP1 and cRGD peptides had a high binding affinity both for activated macrophages and blood clots. Under TUS exposure, the MPmTN could effectively induce macrophage apoptosis, destroy thrombus and exhibit good imaging properties for ultrasound (US) and MRI. In apoE-/- mice, MPmTNs can selectively accumulate at the plaque site and reduce the T2-weighted signal. The apoptosis of macrophages and disaggregation of activated platelets on the plaques were also confirmed in vivo. In summary, this study provides a potential strategy for a tailored treatment of vulnerable plaques based on their pathological nature and a multimodal imaging tool for the risk stratification and assessment of therapeutic efficacy.
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Affiliation(s)
- Binyang Gao
- Department of Ultrasound, Laboratory of Ultrasound Imaging and Drug, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China.
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8
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Sheng D, Deng L, Li P, Wang Z, Zhang Q. Perfluorocarbon Nanodroplets with Deep Tumor Penetration and Controlled Drug Delivery for Ultrasound/Fluorescence Imaging Guided Breast Cancer Therapy. ACS Biomater Sci Eng 2021; 7:605-616. [PMID: 33464814 DOI: 10.1021/acsbiomaterials.0c01333] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Danli Sheng
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
- Department of Ultrasound, Fudan University, Shanghai Cancer Center, Shanghai 200032, China
| | - Liming Deng
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
| | - Pan Li
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
| | - Zhigang Wang
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
| | - Qunxia Zhang
- Institute of Ultrasound Imaging, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P. R. China
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Li DS, Jeng GS, Pitre JJ, Kim M, Pozzo LD, O’Donnell M. Spatially localized sono-photoacoutic activation of phase-change contrast agents. PHOTOACOUSTICS 2020; 20:100202. [PMID: 32817821 PMCID: PMC7424230 DOI: 10.1016/j.pacs.2020.100202] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 05/29/2023]
Abstract
Sono-photoacoustic (SPA) activation lowers the threshold of phase-change contrast agents by timing a laser shot to coincide with the arrival of an acoustic wave at a region of interest. The combination of photothermal heating from optical absorption and negative pressure from the acoustic wave greatly reduces the droplet's combined vaporization threshold compared to using laser energy or acoustic energy alone. In previous studies, SPA imaging used a broadly illuminated optical pulse combined with plane wave acoustic pulses transmitted from a linear ultrasound array. Acoustic plane waves cover a wide lateral field of view, enabling direct visualization of the contrast agent distribution. In contrast, we demonstrate here that localized SPA activation is possible using electronically steered/focused ultrasound pulses. The focused SPA activation region is defined axially by the number of cycles in the acoustic pulse and laterally by the acoustic beam width. By reducing the spot size and enabling rapid electronic steering, complex activation patterns are possible, which may be particularly useful in therapeutic applications.
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Affiliation(s)
- David S. Li
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
- Department of Chemical Engineering, University of Washington, Seattle, WA, 98195 USA
| | - Geng-Shi Jeng
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
| | - John J. Pitre
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
| | - MinWoo Kim
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
| | - Lilo D. Pozzo
- Department of Chemical Engineering, University of Washington, Seattle, WA, 98195 USA
| | - Matthew O’Donnell
- Department of Bioengineering, University of Washington, Seattle, WA, 98195 USA
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Harmon JN, Kabinejadian F, Bull JL. Combined gas embolization and chemotherapy can result in complete tumor regression in a murine hepatocellular carcinoma model. APL Bioeng 2020; 4:036106. [PMID: 32923844 PMCID: PMC7481009 DOI: 10.1063/5.0005329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 08/11/2020] [Indexed: 12/16/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is an intractable cancer with a high mortality rate. Transarterial chemoembolization (TACE), a non-curative method, is the first line therapy for intermediate stage patients. This effectively extends patient survival but requires a complicated intraarterial catheterization procedure and is poorly suited to repeated administration. Here, we investigate gas chemoembolization, a less invasive, more easily administered transient occlusion method that circumvents these limitations. We examined the efficacy of repeated embolization combined with systemically administered doxorubicin, the most common chemotherapeutic in TACE, or tirapazamine, a hypoxia-activated cytotoxic agent, in an ectopic xenograft model of HCC. Emboli were generated in situ using acoustic droplet vaporization, the noninvasive focused ultrasound-mediated conversion of intravenously administered perfluorocarbon microdroplets into microbubbles. Gas embolization alone significantly reduced the Ki67 index and tumor viability (11.6 ± 6.71% non-necrotic vs 100% in control; p < 0.01) after 3 treatments, as assessed by histological analysis. Mice treated for three weeks exhibited significant tumor regression compared to control (23.8 ± 5.37% of initial volume vs 427 ± 49.7% in controls, p < 0.01), irrespective of the chosen chemotherapeutic agent. However, an additional three weeks of monitoring post-treatment elucidated a significant difference in the tumor recurrence rate, with combined gas embolization and doxorubicin resulting in the best treatment outcomes (60% complete regression). While doxorubicin administration resulted in significant cardiotoxicity (p < 0.01), it strongly interacted with the droplet shells, reducing the systemic dose by 11.4%. Overall, gas chemoembolization shows promise as a developmental therapy and merits further study in more complex tumor models.
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Affiliation(s)
- Jennifer N. Harmon
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana 70118, USA
| | - Foad Kabinejadian
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana 70118, USA
| | - Joseph L. Bull
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana 70118, USA
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Sloand JN, Nguyen TT, Zinck SA, Cook EC, Zimudzi TJ, Showalter SA, Glick AB, Simon JC, Medina SH. Ultrasound-Guided Cytosolic Protein Delivery via Transient Fluorous Masks. ACS NANO 2020; 14:4061-4073. [PMID: 32134630 DOI: 10.1021/acsnano.9b08745] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The inability to spatiotemporally guide proteins in tissues and efficiently deliver them into cells remains a key barrier to realizing their full potential in precision medicine. Here, we report ultrasound-sensitive fluoro-protein nanoemulsions which can be acoustically tracked, guided, and activated for on-demand cytosolic delivery of proteins, including antibodies, using clinically relevant diagnostic ultrasound. This advance is accessed through the discovery of a family of fluorous tags, or FTags, that transiently mask proteins to mediate their efficient dispersion into ultrasound-sensitive liquid perfluorocarbons, a phenomenon akin to dissolving an egg in liquid Teflon. We identify the biochemical basis for protein fluorous masking and confirm FTag coatings are shed during delivery, without disrupting the protein structure or function. Harnessing the ultrasound sensitivity of fluorous emulsions, real-time imaging is used to simultaneously monitor and activate FTag-protein complexes to enable controlled cytosolic antibody delivery in vitro and in vivo. These findings may advance the development of image-guided, protein-based biosensing and therapeutic modalities.
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Affiliation(s)
- Janna N Sloand
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Theodore T Nguyen
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Scott A Zinck
- Graduate Program in Acoustics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Erik C Cook
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tawanda J Zimudzi
- Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Scott A Showalter
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Adam B Glick
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Julianna C Simon
- Graduate Program in Acoustics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Scott H Medina
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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12
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Bento D, Lopes S, Maia I, Lima R, Miranda JM. Bubbles Moving in Blood Flow in a Microchannel Network: The Effect on the Local Hematocrit. MICROMACHINES 2020; 11:mi11040344. [PMID: 32224993 PMCID: PMC7230880 DOI: 10.3390/mi11040344] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 01/07/2023]
Abstract
Air inside of blood vessels is a phenomenon known as gas embolism. During the past years, studies have been performed to assess the influence of air bubbles in microcirculation. In this study, we investigated the flow of bubbles in a microchannel network with several bifurcations, mimicking part of a capillary system. Thus, two working fluids were used, composed by sheep red blood cells (RBCs) suspended in a Dextran 40 solution with different hematocrits (5% and 10%). The experiments were carried out in a polydimethylsiloxane (PDMS) microchannel network fabricated by a soft lithography. A high-speed video microscopy system was used to obtain the results for a blood flow rate of 10 µL/min. This system enables the visualization of bubble formation and flow along the network. The results showed that the passage of air bubbles strongly influences the cell's local concentration, since a higher concentration of cells was observed upstream of the bubble, whereas a lower local hematocrit was visualized at the region downstream of the bubble. In bifurcations, bubbles may split asymmetrically, leading to an uneven distribution of RBCs between the outflow branches.
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Affiliation(s)
- David Bento
- CEFT, Faculdade de Engenharia da Universidade do Porto (FEUP) Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (D.B.); (R.L.)
- Polytechnic Institute of Bragança, ESTiG/IPB, C. Sta. Apolónia, 5300-857 Bragança, Portugal;
| | - Sara Lopes
- Polytechnic Institute of Bragança, ESTiG/IPB, C. Sta. Apolónia, 5300-857 Bragança, Portugal;
| | - Inês Maia
- Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
| | - Rui Lima
- CEFT, Faculdade de Engenharia da Universidade do Porto (FEUP) Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (D.B.); (R.L.)
- MEtRICS, Mechanical Eng. Dep., University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal
| | - João M. Miranda
- CEFT, Faculdade de Engenharia da Universidade do Porto (FEUP) Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; (D.B.); (R.L.)
- Correspondence:
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Brambila CJ, Lux J, Mattrey RF, Boyd D, Borden MA, de Gracia Lux C. Bubble Inflation Using Phase-Change Perfluorocarbon Nanodroplets as a Strategy for Enhanced Ultrasound Imaging and Therapy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2954-2965. [PMID: 32090572 DOI: 10.1021/acs.langmuir.9b03647] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Phase-change perfluorocarbon microdroplets were introduced over 2 decades ago to occlude downstream vessels in vivo. Interest in perfluorocarbon nanodroplets has recently increased to enable extravascular targeting, to rescue the weak ultrasound signal of perfluorocarbon droplets by converting them to microbubbles and to improve ultrasound-based therapy. Despite great scientific interest and advances, applications of phase-change perfluorocarbon agents have not reached clinical testing because of efficacy and safety concerns, some of which remain unexplained. Here, we report that the coexistence of perfluorocarbon droplets and microbubbles in blood, which is inevitable when droplets spontaneously or intentionally vaporize to form microbubbles, is a major contributor to the observed side effects. We develop the theory to explain why the coexistence of droplets and microbubbles results in microbubble inflation induced by perfluorocarbon transfer from droplets to adjacent microbubbles. We also present the experimental data showing up to 6 orders of magnitude microbubble volume expansion, which occludes a 200 μm tubing in the presence of perfluorocarbon nanodroplets. More importantly, we demonstrate that the rate of microbubble inflation and ultimate size can be controlled by manipulating formulation parameters to tailor the agent's design for the potential theranostic application while minimizing the risk to benefit ratio.
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Affiliation(s)
- Carlos J Brambila
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Jacques Lux
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Organic Chemistry Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Robert F Mattrey
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Dustin Boyd
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Mark A Borden
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Caroline de Gracia Lux
- Translational Research in Ultrasound Theranostics (TRUST) Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Biomedical Engineering Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
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Ghorbani M, Olofsson K, Benjamins JW, Loskutova K, Paulraj T, Wiklund M, Grishenkov D, Svagan AJ. Unravelling the Acoustic and Thermal Responses of Perfluorocarbon Liquid Droplets Stabilized with Cellulose Nanofibers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13090-13099. [PMID: 31549511 DOI: 10.1021/acs.langmuir.9b02132] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The attractive colloidal and physicochemical properties of cellulose nanofibers (CNFs) at interfaces have recently been exploited in the facile production of a number of environmentally benign materials, e.g. foams, emulsions, and capsules. Herein, these unique properties are exploited in a new type of CNF-stabilized perfluoropentane droplets produced via a straightforward and simple mixing protocol. Droplets with a comparatively narrow size distribution (ca. 1-5 μm in diameter) were fabricated, and their potential in the acoustic droplet vaporization process was evaluated. For this, the particle-stabilized droplets were assessed in three independent experimental examinations, namely temperature, acoustic, and ultrasonic standing wave tests. During the acoustic droplet vaporization (ADV) process, droplets were converted to gas-filled microbubbles, offering enhanced visualization by ultrasound. The acoustic pressure threshold of about 0.62 MPa was identified for the cellulose-stabilized droplets. A phase transition temperature of about 22 °C was observed, at which a significant fraction of larger droplets (above ca. 3 μm in diameter) were converted into bubbles, whereas a large part of the population of smaller droplets were stable up to higher temperatures (temperatures up to 45 °C tested). Moreover, under ultrasound standing wave conditions, droplets were relocated to antinodes demonstrating the behavior associated with the negative contrast particles. The combined results make the CNF-stabilized droplets interesting in cell-droplet interaction experiments and ultrasound imaging.
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Affiliation(s)
- Morteza Ghorbani
- Department of Biomedical Engineering and Health Systems , KTH Royal Institute of Technology , SE-100 44 Stockholm , Sweden
- Mechatronics Engineering Program, Faculty of Engineering and Natural Science , Sabanci University , Istanbul 34956 , Turkey
| | - Karl Olofsson
- Department of Applied Physics , KTH Royal Institute of Technology SE-100 44 Stockholm , Sweden
| | - Jan-Willem Benjamins
- Research Institute of Sweden (RISE) , Chemistry, Materials and Surfaces , Box 5607, SE-114 86 Stockholm , Sweden
| | - Ksenia Loskutova
- Department of Biomedical Engineering and Health Systems , KTH Royal Institute of Technology , SE-100 44 Stockholm , Sweden
| | - Thomas Paulraj
- Department of Fiber and Polymer Technology , KTH Royal Institute of Technology , SE-100 44 Stockholm , Sweden
| | - Martin Wiklund
- Department of Applied Physics , KTH Royal Institute of Technology SE-100 44 Stockholm , Sweden
| | - Dmitry Grishenkov
- Department of Biomedical Engineering and Health Systems , KTH Royal Institute of Technology , SE-100 44 Stockholm , Sweden
| | - Anna J Svagan
- Department of Fiber and Polymer Technology , KTH Royal Institute of Technology , SE-100 44 Stockholm , Sweden
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15
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Mercado-Shekhar KP, Su H, Kalaikadal DS, Lorenz JN, Manglik RM, Holland CK, Redington AN, Haworth KJ. Acoustic droplet vaporization-mediated dissolved oxygen scavenging in blood-mimicking fluids, plasma, and blood. ULTRASONICS SONOCHEMISTRY 2019; 56:114-124. [PMID: 31101245 PMCID: PMC6659737 DOI: 10.1016/j.ultsonch.2019.03.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/20/2018] [Accepted: 03/27/2019] [Indexed: 05/20/2023]
Abstract
Acoustic droplet vaporization (ADV) has been shown to reduce the partial pressure of oxygen (PO2) in a fluid. The goals of this study were three-fold: 1) to determine the ADV pressure amplitude threshold in fluids that had physiologically relevant values for surface tension, protein concentration, and viscosity; 2) to assess whether these parameters and fluid mixing affect ADV-mediated PO2 reduction; and 3) to assess the feasibility of ADV-mediated PO2 reduction in plasma and whole blood. In vitro ADV experiments were conducted using perfluoropentane droplets (number density: 5 × 106 ± 0.2 × 106/mL) dispersed in fluids (saline, polyvinylpyrrolidone solutions, porcine plasma, or porcine whole blood) that had a physiological range of surface tensions (62-68 mN/m), protein concentrations (0 and 68.7 mg/mL), and viscosities (0.7-4 cP). Droplets were exposed to pulsed ultrasound (5 MHz, 4.25 MPa peak negative pressure) while passing through a 37 °C flow system with inline PO2 sensors. In select experiments, the fluid also passed through mixing channels after ultrasound exposure. Our results revealed that the ADV pressure thresholds were the same for all fluids. Surface tension and protein concentration had no effect on PO2 reduction. Increasing viscosity attenuated PO2 reduction. However, the attenuated effect was absent after fluid mixing. Furthermore, ADV-mediated PO2 reduction in whole blood (30.8 ± 3.2 mmHg) was less than that in a polyvinylpyrrolidone solution (40.2 ± 2.1 mmHg) with equal viscosity. These findings should be considered when planning clinical studies of ADV-mediated PO2 reduction and other biomedical applications of ADV.
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Affiliation(s)
| | - Haili Su
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Deepak S Kalaikadal
- Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - John N Lorenz
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH, USA
| | - Raj M Manglik
- Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Christy K Holland
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Andrew N Redington
- Division of Cardiology, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kevin J Haworth
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA; Division of Cardiology, The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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16
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Harmon JN, Kabinejadian F, Seda R, Fabiilli ML, Kuruvilla S, Kuo CC, Greve JM, Fowlkes JB, Bull JL. Minimally invasive gas embolization using acoustic droplet vaporization in a rodent model of hepatocellular carcinoma. Sci Rep 2019; 9:11040. [PMID: 31363130 PMCID: PMC6667465 DOI: 10.1038/s41598-019-47309-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 07/11/2019] [Indexed: 12/19/2022] Open
Abstract
Hepatocellular carcinoma is the third leading cause of cancer-related deaths worldwide. Many patients are not eligible for curative therapies, such as surgical resection of the tumor or a liver transplant. Transarterial embolization is one therapy clinically used in these cases; however, this requires a long procedure and careful placement of an intraarterial catheter. Gas embolization has been proposed as a fast, easily administered, more spatially selective, and less invasive alternative. Here, we demonstrate the feasibility and efficacy of using acoustic droplet vaporization to noninvasively generate gas emboli within vasculature. Intravital microscopy experiments were performed using the rat cremaster muscle to visually observe the formation of occlusions. Large gas emboli were produced within the vasculature in the rat cremaster, effectively occluding blood flow. Following these experiments, the therapeutic efficacy of gas embolization was investigated in an ectopic xenograft model of hepatocellular carcinoma in mice. The treatment group exhibited a significantly lower final tumor volume (ANOVA, p = 0.008) and growth rate than control groups - tumor growth was completely halted. Additionally, treated tumors exhibited significant necrosis as determined by histological analysis. To our knowledge, this study is the first to demonstrate the therapeutic efficacy of gas embolotherapy in a tumor model.
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Affiliation(s)
- Jennifer N Harmon
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, USA
| | - Foad Kabinejadian
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, USA
| | - Robinson Seda
- Data Office for Clinical and Translational Research, University of Michigan, Ann Arbor, Michigan, USA
| | - Mario L Fabiilli
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sibu Kuruvilla
- Department of Oncology, Stanford University, Stanford, California, USA
| | - Cathleen C Kuo
- Department of Neuroscience, Tulane University, New Orleans, Louisiana, USA
| | - Joan M Greve
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - J Brian Fowlkes
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Joseph L Bull
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana, USA.
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17
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Loskutova K, Grishenkov D, Ghorbani M. Review on Acoustic Droplet Vaporization in Ultrasound Diagnostics and Therapeutics. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9480193. [PMID: 31392217 PMCID: PMC6662494 DOI: 10.1155/2019/9480193] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/10/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023]
Abstract
Acoustic droplet vaporization (ADV) is the physical process in which liquid undergoes phase transition to gas after exposure to a pressure amplitude above a certain threshold. In recent years, new techniques in ultrasound diagnostics and therapeutics have been developed which utilize microformulations with various physical and chemical properties. The purpose of this review is to give the reader a general idea on how ADV can be implemented for the existing biomedical applications of droplet vaporization. In this regard, the recent developments in ultrasound therapy which shed light on the ADV are considered. Modern designs of capsules and nanodroplets (NDs) are shown, and the material choices and their implications for function are discussed. The influence of the physical properties of the induced acoustic field, the surrounding medium, and thermophysical effects on the vaporization are presented. Lastly, current challenges and potential future applications towards the implementation of the therapeutic droplets are discussed.
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Affiliation(s)
- Ksenia Loskutova
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, SE-141 57 Huddinge, Sweden
| | - Dmitry Grishenkov
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, SE-141 57 Huddinge, Sweden
| | - Morteza Ghorbani
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, SE-141 57 Huddinge, Sweden
- Mechatronics Engineering Program, Faculty of Engineering and Natural Science, Sabanci University, Istanbul 34956, Turkey
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18
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Mannaris C, Bau L, Grundy M, Gray M, Lea-Banks H, Seth A, Teo B, Carlisle R, Stride E, Coussios CC. Microbubbles, Nanodroplets and Gas-Stabilizing Solid Particles for Ultrasound-Mediated Extravasation of Unencapsulated Drugs: An Exposure Parameter Optimization Study. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:954-967. [PMID: 30655109 DOI: 10.1016/j.ultrasmedbio.2018.10.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/24/2018] [Accepted: 10/31/2018] [Indexed: 06/09/2023]
Abstract
Ultrasound-induced cavitation has been proposed as a strategy to tackle the challenge of inadequate extravasation, penetration and distribution of therapeutics into tumours. Here, the ability of microbubbles, droplets and solid gas-trapping particles to facilitate mass transport and extravasation of a model therapeutic agent following ultrasound-induced cavitation is investigated. Significant extravasation and penetration depths on the order of millimetres are achieved with all three agents, including the range of pressures and frequencies achievable with existing clinical ultrasound systems. Deeper but highly directional extravasation was achieved with frequencies of 1.6 and 3.3 MHz compared with 0.5 MHz. Increased extravasation was observed with increasing pulse length and exposure time, while an inverse relationship is observed with pulse repetition frequency. No significant cell death or any haemolytic activity in human blood was observed at clinically relevant concentrations for any of the agents. Overall, solid gas-trapping nanoparticles were found to enable the most extensive extravasation for the lowest input acoustic energy, followed by microbubbles and then droplets. The ability of these agents to produce sustained inertial cavitation activity whilst being small enough to follow the drug out of the circulation and into diseased tissue, combined with a good safety profile and the possibility of real-time monitoring, offers considerable potential for enhanced drug delivery of unmodified drugs in oncological and other biomedical applications.
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Affiliation(s)
- Christophoros Mannaris
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Luca Bau
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Megan Grundy
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Michael Gray
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Harriet Lea-Banks
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Anjali Seth
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Boon Teo
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Robert Carlisle
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Eleanor Stride
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom
| | - Constantin C Coussios
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Headington, Oxford, United Kingdom.
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19
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Chao C, Jin X, Teng L, Stokes AA, Fan X. Bubble Dislodgment in a Capillary Network with Microscopic Multichannels and Multibifurcation Features. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3194-3203. [PMID: 30721065 DOI: 10.1021/acs.langmuir.8b03323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Bubble lodgment in a complex capillary network is a common issue in many industrial and biological processes. Research work reported in the literature only investigated bubble dislodgment in single channels and did not consider the effect of network complexity on the dislodgment. This paper focuses on the pressure required to dislodge single bubbles from a microscopic capillary network and investigates the factors affecting the dislodging pressure to facilitate the precise control of bubble flows in porous media. A capillary network with multibifurcation and a smoothly changed diameter is designed to closely mimic the structure of the physiological vascular networks. Over 600 bubble dislodgment experiments have been conducted to understand the effect of the network structure, channel dimensions, and bubble length on the dislodging pressure. The results indicate that the network structure is a dominant factor affecting the dislodging pressure that increases with the increase in network complexity. The effect of bubble length on the dislodging pressure depends on the bubble length. When the bubble length is less than a certain value, which is around 2 mm in this study, the dislodging pressure increases significantly with the decrease of bubble length. When the bubble length is larger than 2 mm, the dislodging pressure is independent of the bubble length. A model has been proposed to explain the bubble dislodgment in complex capillary networks. The impact of the network structure on the bubble dislodging pressure is characterized by a parameter c j. The model indicates that the dislodging pressure is the function of bubble length, channel dimension, and network structure. The analysis of model parameters NB j and MA j shows that parameter c j, rather than the channel size, dominates the dislodging pressure for bubbles with a length greater than 2 mm, and the increase rate of the dislodging pressure is significantly affected by both channel size and parameter c j.
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Affiliation(s)
- Cong Chao
- Institute for Materials and Processes, School of Engineering , The University of Edinburgh , The King's Buildings, Robert Stevenson Road , Edinburgh EH9 3FB , U.K
| | - Xiaoqiang Jin
- Institute for Materials and Processes, School of Engineering , The University of Edinburgh , The King's Buildings, Robert Stevenson Road , Edinburgh EH9 3FB , U.K
| | - Lijun Teng
- Institute for Integrated Micro and Nano Systems, School of Engineering , The University of Edinburgh , The King's Buildings, Alexander Crum Brown Road , Edinburgh EH9 3FB , U.K
| | - Adam A Stokes
- Institute for Integrated Micro and Nano Systems, School of Engineering , The University of Edinburgh , The King's Buildings, Alexander Crum Brown Road , Edinburgh EH9 3FB , U.K
| | - Xianfeng Fan
- Institute for Materials and Processes, School of Engineering , The University of Edinburgh , The King's Buildings, Robert Stevenson Road , Edinburgh EH9 3FB , U.K
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20
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Li DS, Schneewind S, Bruce M, Khaing Z, O’Donnell M, Pozzo L. Spontaneous Nucleation of Stable Perfluorocarbon Emulsions for Ultrasound Contrast Agents. NANO LETTERS 2019; 19:173-181. [PMID: 30543289 PMCID: PMC7970446 DOI: 10.1021/acs.nanolett.8b03585] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Phase-change contrast agents are rapidly developing as an alternative to microbubbles for ultrasound imaging and therapy. These agents are synthesized and delivered as liquid droplets and vaporized locally to produce image contrast. They can be used like conventional microbubbles but with the added benefit of reduced size and improved stability. Droplet-based agents can be synthesized with diameters on the order of 100 nm, making them an ideal candidate for extravascular imaging or therapy. However, their synthesis requires low boiling point perfluorocarbons (PFCs) to achieve activation (i.e., vaporization) thresholds within FDA approved limits. Minimizing spontaneous vaporization while producing liquid droplets using conventional methods with low boiling point PFCs can be challenging. In this study, a new method to produce PFC nanodroplets using spontaneous nucleation is demonstrated using PFCs with boiling points ranging from -37 to 56 °C. Sometimes referred to as the ouzo method, the process relies on saturating a cosolvent with the PFC before adding a poor solvent to reduce solvent quality, forcing droplets to spontaneously nucleate. This approach can produce droplets ranging from under 100 nm to over 1 μm in diameter. Ternary plots showing solvent and PFC concentrations leading to droplet nucleation are presented. Additionally, acoustic activation thresholds and size distributions with varying PFC and solvent conditions are measured and discussed. Finally, ultrasound contrast imaging is demonstrated using ouzo droplets in an animal model.
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Affiliation(s)
- David S. Li
- Department of Chemical Engineering, University of
Washington, Seattle, WA
- Department of Bioengineering, University of Washington,
Seattle, WA
| | - Sarah Schneewind
- Department of Chemical Engineering, University of
Washington, Seattle, WA
| | - Matthew Bruce
- Center for Industrial and Medical Ultrasound, Applied
Physics Lab, University of Washington, Seattle, WA
| | - Zin Khaing
- Department of Neurological Surgery, University of
Washington, Seattle, WA
| | | | - Lilo Pozzo
- Department of Chemical Engineering, University of
Washington, Seattle, WA
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21
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Rojas JD, Dayton PA. Vaporization Detection Imaging: A Technique for Imaging Low-Boiling-Point Phase-Change Contrast Agents with a High Depth of Penetration and Contrast-to-Tissue Ratio. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:192-207. [PMID: 30482709 DOI: 10.1016/j.ultrasmedbio.2018.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 08/17/2018] [Accepted: 08/22/2018] [Indexed: 06/09/2023]
Abstract
Phase-change contrast agents (PCCAs) possess advantages over microbubble contrast agents, such as the ability to extravasate and circulate longer in the vasculature that could enhance the diagnostic capabilities of contrast-enhanced ultrasound. PCCAs typically have a liquid perfluorocarbon (PFC) core that can be vaporized into echogenic microbubbles. Vaporization of submicron agents filled with liquid PFCs at body temperature usually requires therapeutic pressures higher than typically used for diagnostic imaging, but low-boiling-point PCCAs using decafluorobutane or octafluoropropane can be vaporized using pressures in the diagnostic imaging regime. Low-boiling-point PCCAs produce a unique acoustic signature that can be separated from tissue and bubble signals to make images with high contrast-to-tissue ratios. In this work, we explore the effect of pulse length and concentration on the vaporization signal of PCCAs and a new technique to capture and use the signals to make high contrast-to-tissue ratio images in vivo. The results indicate that using a short pulse may be ideal for imaging because it does not interact with created bubbles but still produces strong signals for making images. Furthermore, it was found that capturing PCCA vaporization signals produced higher contrast-to-tissue ratio values and better depth of penetration than imaging the bubbles generated by droplet activation using conventional contrast imaging techniques. The resolution of the vaporization signal images is poor because of the low frequency of the signals, but their high sensitivity may be used for applications such as molecular imaging, where the detection of small numbers of contrast agents is important.
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Affiliation(s)
- Juan D Rojas
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA.
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22
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Ho YJ, Wu CC, Hsieh ZH, Fan CH, Yeh CK. Thermal-sensitive acoustic droplets for dual-mode ultrasound imaging and drug delivery. J Control Release 2018; 291:26-36. [DOI: 10.1016/j.jconrel.2018.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 10/11/2018] [Accepted: 10/14/2018] [Indexed: 12/23/2022]
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23
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Fan CH, Lin YT, Ho YJ, Yeh CK. Spatial-Temporal Cellular Bioeffects from Acoustic Droplet Vaporization. Theranostics 2018; 8:5731-5743. [PMID: 30555577 PMCID: PMC6276289 DOI: 10.7150/thno.28782] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/16/2018] [Indexed: 01/04/2023] Open
Abstract
One of the major challenges in developing acoustic droplet vaporization (ADV)-associated therapy as an effective and safe strategy is the precise determination of the spatial cellular bioeffects after ADV (cell death or cell membrane permeabilization). In this study, we combined high-speed camera imaging and live-cell microscopic imaging to observe the transient dynamics of droplets during ADV and to evaluate the mechanical force on cells. Methods: C6 glioma cells were co-incubated with DiI-labeled droplets (radius: 1.5, 2.25, and 3.0 μm). We used an acousto-optical system for high-speed bright-field (500 kfps) and fluorescence (40 kfps) microscopic imaging in order to visualize the dynamics of droplets under ultrasound excitation (frequency = 5 MHz, pressure = 5-8 MPa, cycle number = 3, pulse number = 1). Live-cell microscopic imaging was used to monitor the cell morphology, cell membrane permeabilization, and cell viability by membrane-anchored Lyn-yellow fluorescence protein, propidium Iodide staining, and calcein blue AM staining, respectively. Results: We discovered that the spatial distribution of ADV-induced bioeffects could be mapped to the physical dynamics of droplet vaporization. For droplets with a 1.5 μm radius, the distance threshold for ADV-induced cell death (5.5±1.9 μm) and reversible membrane permeabilization (11.3±3.5 μm) was well correlated with the distance of ADV-bubble pressing downward to the floor (5.7±1.3 μm) and maximum distance of droplet expansion (11.5±2.6 μm), respectively. These distances were enlarged by increasing the droplet sizes and insonation acoustic pressures. The live-cell imaging results show that ADV-bubbles can directly disrupt the cell membrane layer and induce intensive intracellular substance leakage. Further, the droplets shed the payload onto nearby cells during ADV, suggesting ADV could directly induce adjacent cell death by physical force and enhancement of chemotherapy to distant cells. Conclusion: This study provide new insights into the ADV-mediated physicochemical synergic effect for medical applications.
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24
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Shervani-Tabar MT, Farzaneh B, Ahrabi R, Razavi SE. Numerical study on the impulsive growth of a gaseous plug inside a cylindrical vein with compliant coating. ACTA ACUST UNITED AC 2018; 8:271-279. [PMID: 30397582 PMCID: PMC6209829 DOI: 10.15171/bi.2018.30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 09/10/2017] [Accepted: 09/11/2017] [Indexed: 11/22/2022]
Abstract
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Introduction: Employing of gaseous plugs inside a vein for preventing of blood flow to the damaged or cancerous tissues has been known as a gas embolism in the medicine. In this research, a numerical investigation has been carried out on the delivery of the liquid drug DDFP, encapsulated in the microlipidcoated spheres (MLCSs), to target the human vein for construction of the gaseous plug inside the veins.
Methods: The encapsulated liquid drug DDFP were delivered to the vein by injection of an emulsion. Releasing of the liquid drug DDFP results in an explosive growth of a gaseous plug inside the vein. The targeted vein was served as a rigid cylinder with a compliant coating. The boundary integral equation method has been employed for the numerical simulation of the hydrodynamic behavior of the gaseous plug inside the vein.
Results: Numerical results showed that in the case of a rigid cylinder vein with an internal compliant coating, the maximum volume of the gaseous plug was smaller than the case of just a rigid cylinder vein. Furthermore, its elapsed time from the instant of bubble generation to the instant when the bubble reaches its maximum volume was shorter. Numerical results also showed that the compliant coating on the internal wall of the rigid cylindrical vein had a tendency of reducing the impact of the explosive growth of the gaseous plug.
Conclusion: This numerical research showed that the compliant coating on the internal wall of the rigid cylindrical vein had the tendency of reducing the impact of the impulsive growth of the gaseous plug. Therefore, in the case of having severed arteriosclerosis, treatment of the cancerous or damaged tissues by use of the gaseous embolism must be done very carefully in order to prevent the hazardous effects of the gaseous plug’s impulsive growth.
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Affiliation(s)
- Mohammad T Shervani-Tabar
- Center for CFD Studies on Heat Engines, Cavitational Flows, and Petroleum Industries, School of Mechanical Engineering, University of Tabriz, Iran
| | - Babak Farzaneh
- Center for CFD Studies on Heat Engines, Cavitational Flows, and Petroleum Industries, School of Mechanical Engineering, University of Tabriz, Iran
| | - Reza Ahrabi
- Department of Interventional Radiology, Alinasab Hospital, Tabriz, Iran
| | - Seyed E Razavi
- School of Mechanical Engineering, University of Tabriz, Tabriz, Iran
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25
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Fan CH, Lee YH, Ho YJ, Wang CH, Kang ST, Yeh CK. Macrophages as Drug Delivery Carriers for Acoustic Phase-Change Droplets. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:1468-1481. [PMID: 29685589 DOI: 10.1016/j.ultrasmedbio.2018.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 03/06/2018] [Accepted: 03/14/2018] [Indexed: 05/19/2023]
Abstract
The major challenges in treating malignant tumors are transport of therapeutic agents to hypoxic regions and real-time assessment of successful drug release via medical imaging modalities. In this study, we propose the use of macrophages (RAW 264.7 cells) as carriers of drug-loaded phase-change droplets to penetrate ischemic or hypoxic regions within tumors. The droplets consist of perfluoropentane, lipid and the chemotherapeutic drug doxorubicin (DOX, DOX-droplets). The efficiency of DOX-droplet uptake, migration mobility and viability of DOX-droplet-loaded macrophages (DLMs) were measured using a transmembrane cell migration assay, the alamarBlue assay and flow cytometric analysis, respectively. Our results indicate the feasibility of utilizing macrophages as DOX-droplet carriers (DOX payload of DOX-droplets: 459.3 ± 35.8 µg/mL, efficiency of cell uptake DOX-droplets: 88.8 ± 3.5%). The migration mobility (total number of migrated microphages) of DLMs decreased to 32.3% compared with that of healthy macrophages, but the DLMs provided contrast-enhanced ultrasound imaging (1.7-fold enhancement) and anti-tumor effect (70.9% cell viability) after acoustic droplet vaporization, suggesting the potential theranostic applications of DLMs. Future work will assess the tumor penetration ability of DLMs, mechanical effect of droplet vaporization on in vivo anti-tumor therapy and the release of the carried drug by ultrasound-triggered vaporization.
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Affiliation(s)
- Ching-Hsiang Fan
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Ya-Hsuan Lee
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Yi-Ju Ho
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Chung-Hsin Wang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Shih-Tsung Kang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Chih-Kuang Yeh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
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26
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Harmon JN, Kabinejadian F, Seda R, Fabiilli ML, Kuruvilla SP, Greve JM, Fowlkes BJ, Bull JL. Gas Embolization in a Rodent Model of Hepatocellular Carcinoma Using Acoustic Droplet Vaporization. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:6048-6051. [PMID: 30441715 PMCID: PMC6839763 DOI: 10.1109/embc.2018.8513518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Trans-arterial embolization is a commonly used therapy in unresectable hepatocellular carcinoma. Current methods involve the careful placement of an intraarterial catheter and the deposition of embolizing particles. Gas embolotherapy has been proposed as an embolization method with the potential for high spatial resolution without the need for a catheter. This method involves vaporizing intravenouslyadministered droplets into gas bubbles using focused ultrasound - a process termed acoustic droplet vaporization. The bubbles can become lodged in the vasculature, thereby creating an embolus. Here, we initially demonstrate the feasibility of achieving significant targeted embolization with this method in the rat cremaster using intravital microscopy. The therapy was then tested in an ectopic xenograft mouse model of hepatocellular carcinoma. Gas embolotherapy was shown to maintain the tumor volume at baseline over a twoweek treatment course while control groups showed significant tumor growth. These preliminary results demonstrate thatgas embolotherapy could serve as an effective noninvasive method for the management of unresectable hepatocellular carcinoma.
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Aliabouzar M, Kumar KN, Sarkar K. Acoustic vaporization threshold of lipid-coated perfluoropentane droplets. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2018; 143:2001. [PMID: 29716255 PMCID: PMC5895468 DOI: 10.1121/1.5027817] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Phase shift droplets vaporizable by acoustic stimulation offer the advantages of producing microbubbles as contrast agents in situ as well as higher stability and the possibility of achieving smaller sizes. Here, the acoustic droplet vaporization (ADV) threshold of a suspension of droplets with a perfluoropentane (PFP) core (diameter 400-3000 nm) is acoustically measured as a function of the excitation frequency in a tubeless setup at room temperature. The changes in scattered responses-fundamental, sub-, and second harmonic-are investigated, a quantitative criterion is used to determine the ADV phenomenon, and findings are discussed. The average threshold obtained using three different scattered components increases with frequency-1.05 ± 0.28 MPa at 2.25 MHz, 1.89 ± 0.57 MPa at 5 MHz, and 2.34 ± 0.014 MPa at 10 MHz. The scattered response from vaporized droplets was also found to qualitatively match with that from an independently prepared lipid-coated microbubble suspension in magnitude as well as trends above the determined ADV threshold value.
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Affiliation(s)
- Mitra Aliabouzar
- Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC 20052, USA
| | - Krishna N Kumar
- Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC 20052, USA
| | - Kausik Sarkar
- Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC 20052, USA
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Wu SY, Fix SM, Arena CB, Chen CC, Zheng W, Olumolade OO, Papadopoulou V, Novell A, Dayton PA, Konofagou EE. Focused ultrasound-facilitated brain drug delivery using optimized nanodroplets: vaporization efficiency dictates large molecular delivery. Phys Med Biol 2018; 63:035002. [PMID: 29260735 DOI: 10.1088/1361-6560/aaa30d] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Focused ultrasound with nanodroplets could facilitate localized drug delivery after vaporization with potentially improved in vivo stability, drug payload, and minimal interference outside of the focal zone compared with microbubbles. While the feasibility of blood-brain barrier (BBB) opening using nanodroplets has been previously reported, characterization of the associated delivery has not been achieved. It was hypothesized that the outcome of drug delivery was associated with the droplet's sensitivity to acoustic energy, and can be modulated with the boiling point of the liquid core. Therefore, in this study, octafluoropropane (OFP) and decafluorobutane (DFB) nanodroplets were used both in vitro for assessing their relative vaporization efficiency with high-speed microscopy, and in vivo for delivering molecules with a size relevant to proteins (40 kDa dextran) to the murine brain. It was found that at low pressures (300-450 kPa), OFP droplets vaporized into a greater number of microbubbles compared to DFB droplets at higher pressures (750-900 kPa) in the in vitro study. In the in vivo study, successful delivery was achieved with OFP droplets at 300 kPa and 450 kPa without evidence of cavitation damage using ¼ dosage, compared to DFB droplets at 900 kPa where histology indicated tissue damage due to inertial cavitation. In conclusion, the vaporization efficiency of nanodroplets positively impacted the amount of molecules delivered to the brain. The OFP droplets due to the higher vaporization efficiency served as better acoustic agents to deliver large molecules efficiently to the brain compared with the DFB droplets.
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Affiliation(s)
- Shih-Ying Wu
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
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Pellow C, Goertz DE, Zheng G. Breaking free from vascular confinement: status and prospects for submicron ultrasound contrast agents. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2017; 10:e1502. [PMID: 29148219 DOI: 10.1002/wnan.1502] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/23/2017] [Accepted: 09/30/2017] [Indexed: 12/11/2022]
Abstract
The development of encapsulated microbubbles (~1-6 μm) has expanded the utility of ultrasound from soft tissue anatomical imaging to not only functional intravascular imaging, but therapeutic interventions, with compelling studies of elicited biological effects. The large diameter of these bubbles has confined their utility to the vasculature, but converging interdisciplinary research pathways are giving rise to new submicron ultrasound contrast agents capable of extending their effects beyond the vascular compartment. This article reviews the status and prospects of exogenous agents including nanobubbles, echogenic liposomes, gas vesicles, cavitation seeds, and nanodroplets, and assesses outstanding criticisms preventing their advance. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Emerging Technologies.
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Affiliation(s)
- Carly Pellow
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Sunnybrook Research Institute, Toronto, Canada.,Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - David E Goertz
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Sunnybrook Research Institute, Toronto, Canada
| | - Gang Zheng
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
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de Gracia Lux C, Vezeridis AM, Lux J, Armstrong AM, Sirsi SR, Hoyt K, Mattrey RF. Novel method for the formation of monodisperse superheated perfluorocarbon nanodroplets as activatable ultrasound contrast agents. RSC Adv 2017; 7:48561-48568. [PMID: 29430294 PMCID: PMC5801773 DOI: 10.1039/c7ra08971f] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microbubble (MB) contrast agents have positively impacted the clinical ultrasound (US) community worldwide. Their use in molecular US imaging applications has been hindered by their limited distribution to the vascular space. Acoustic droplet vaporization (ADV) of nanoscale superheated perfluorocarbon nanodroplets (NDs) demonstrates potential as an extravascular contrast agent that could facilitate US-based molecular theranostic applications. However these agents are metastable and difficult to manufacture with high yields. Here, we report a new formulation technique that yields reliable, narrowly dispersed sub-300 nm decafluorobutane (DFB) or octafluoropropane (OFP)-filled phospholipid-coated NDs that are stable at body temperature, using small volume microfluidization. Final droplet concentration was high for DFB and lower for OFP (>1012vs. >1010 NDs per mL). Superheated ND stability was quantified using tunable resistive pulse sensing (TRPS) and dynamic light scattering (DLS). DFB NDs were stable for at least 2 hours at body temperature (37 °C) without spontaneous vaporization. These NDs are activatable in vitro when exposed to diagnostic US pressures delivered by a clinical system to become visible microbubbles. The DFB NDs were suficiently stable to allow their processing into functionalized NDs with anti-epithelial cell adhesion molecule (EpCAM) antibodies to target EpCAM positive cells.
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Affiliation(s)
- C de Gracia Lux
- Department of Radiology, Translational Research in Ultrasound Theranostics (TRUST) Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - A M Vezeridis
- Department of Radiology, University of California, La Jolla, San Diego, CA 92093, USA
| | - J Lux
- Department of Radiology, Translational Research in Ultrasound Theranostics (TRUST) Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - A M Armstrong
- Department of Radiology, Translational Research in Ultrasound Theranostics (TRUST) Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - S R Sirsi
- Department of Radiology, Translational Research in Ultrasound Theranostics (TRUST) Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - K Hoyt
- Department of Radiology, Translational Research in Ultrasound Theranostics (TRUST) Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - R F Mattrey
- Department of Radiology, Translational Research in Ultrasound Theranostics (TRUST) Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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31
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Li DS, Yoon SJ, Pelivanov I, Frenz M, O’Donnell M, Pozzo LD. Polypyrrole-Coated Perfluorocarbon Nanoemulsions as a Sono-Photoacoustic Contrast Agent. NANO LETTERS 2017; 17:6184-6194. [PMID: 28926276 PMCID: PMC5636685 DOI: 10.1021/acs.nanolett.7b02845] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
A new contrast agent for combined photoacoustic and ultrasound imaging is presented. It has a liquid perfluorocarbon (PFC) core of about 250 nm diameter coated by a 30 nm thin polypyrrole (PPy) doped polymer shell emulsion that represents a broadband absorber covering the visible and near-infrared ranges (peak optical extinction at 1050 nm). When exposed to a sufficiently high intensity optical or acoustic pulse, the droplets vaporize to form microbubbles providing a strong increase in imaging sensitivity and specificity. The threshold for contrast agent activation can further drastically be reduced by up to 2 orders of magnitude if simultaneously exposing them with optical and acoustic pulses. The selection of PFC core liquids with low boiling points (i.e., perfluorohexane (56 °C), perfluoropentane (29 °C), and perfluorobutane (-2 °C)) facilitates activation and reduces the activation threshold of PPy-coated emulsion contrast agents to levels well within clinical safety limits (as low as 0.2 MPa at 1 mJ/cm2). Finally, the potential use of these nanoemulsions as a contrast agent is demonstrated in a series of phantom imaging studies.
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Affiliation(s)
- David S. Li
- Department of Chemical Engineering, University of Washington, Seattle, Washington, 98195, USA
| | - Soon Joon Yoon
- Department of Bioengineering, University of Washington, Seattle, Washington, 98195, USA
| | - Ivan Pelivanov
- Department of Bioengineering, University of Washington, Seattle, Washington, 98195, USA
- International Laser Center, Moscow State University, Moscow, 119992, Russia
| | - Martin Frenz
- Institute of Applied Physics, University of Bern, Bern, CH-3012, Switzerland
| | - Matthew O’Donnell
- International Laser Center, Moscow State University, Moscow, 119992, Russia
| | - Lilo D. Pozzo
- Department of Chemical Engineering, University of Washington, Seattle, Washington, 98195, USA
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Bento D, Sousa L, Yaginuma T, Garcia V, Lima R, Miranda JM. Microbubble moving in blood flow in microchannels: effect on the cell-free layer and cell local concentration. Biomed Microdevices 2017; 19:6. [PMID: 28092011 DOI: 10.1007/s10544-016-0138-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Gas embolisms can hinder blood flow and lead to occlusion of the vessels and ischemia. Bubbles in microvessels circulate as tubular bubbles (Taylor bubbles) and can be trapped, blocking the normal flow of blood. To understand how Taylor bubbles flow in microcirculation, in particular, how bubbles disturb the blood flow at the scale of blood cells, experiments were performed in microchannels at a low Capillary number. Bubbles moving with a stream of in vitro blood were filmed with the help of a high-speed camera. Cell-free layers (CFLs) were observed downstream of the bubble, near the microchannel walls and along the centerline, and their thicknesses were quantified. Upstream to the bubble, the cell concentration is higher and CFLs are less clear. While just upstream of the bubble the maximum RBC concentration happens at positions closest to the wall, downstream the maximum is in an intermediate region between the centerline and the wall. Bubbles within microchannels promote complex spatio-temporal variations of the CFL thickness along the microchannel with significant relevance for local rheology and transport processes. The phenomenon is explained by the flow pattern characteristic of low Capillary number flows. Spatio-temporal variations of blood rheology may have an important role in bubble trapping and dislodging.
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Affiliation(s)
- David Bento
- School of Technology and Management (ESTiG), Polytechnic Institute of Bragança (IPB), Campus de Santa Apolónia, 5300-253, Bragança, Portugal
- Transport Phenomena Research Center (CEFT), Department of Chemical Engineering, Engineering Faculty, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Lúcia Sousa
- School of Technology and Management (ESTiG), Polytechnic Institute of Bragança (IPB), Campus de Santa Apolónia, 5300-253, Bragança, Portugal
| | - Tomoko Yaginuma
- School of Technology and Management (ESTiG), Polytechnic Institute of Bragança (IPB), Campus de Santa Apolónia, 5300-253, Bragança, Portugal
| | - Valdemar Garcia
- School of Technology and Management (ESTiG), Polytechnic Institute of Bragança (IPB), Campus de Santa Apolónia, 5300-253, Bragança, Portugal
| | - Rui Lima
- MEtRiS, Department of Mechanical Engineering, Minho University, Campus de Azurém, 4800-058, Guimarães, Portugal
- Transport Phenomena Research Center (CEFT), Department of Chemical Engineering, Engineering Faculty, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - João M Miranda
- Transport Phenomena Research Center (CEFT), Department of Chemical Engineering, Engineering Faculty, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal.
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Niu C, Xu Y, An S, Zhang M, Hu Y, Wang L, Peng Q. Near-infrared induced phase-shifted ICG/Fe 3O 4 loaded PLGA nanoparticles for photothermal tumor ablation. Sci Rep 2017; 7:5490. [PMID: 28710483 PMCID: PMC5511230 DOI: 10.1038/s41598-017-06122-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/07/2017] [Indexed: 02/05/2023] Open
Abstract
Near-infrared (NIR) laser-induced photothermal therapy (PTT) uses a photothermal agent to convert optical energy into thermal energy and has great potential as an effective local, minimally invasive treatment modality for killing cancer cells. To improve the efficacy of PTT, we developed poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) encapsulating superparamagnetic iron oxide (Fe3O4), indocyanine green (ICG), and perfluoropentane (PFP) as synergistic agents for NIR laser-induced PTT. We fabricated a novel type of phase-shifting fluorescent magnetic NPs, Fe3O4/ICG@PLGA/PFP NPs, that effectively produce heat in response to NIR laser irradiation for an enhanced thermal ablation effect and a phase-shift thermoelastic expansion effect, and thus, can be used as a photothermal agent. After in vitro treatment of MCF-7 breast cancer cells with Fe3O4/ICG@PLGA/PFP NPs and NIR laser irradiation, histology and electron microscopy confirmed severe damage to the cells and the formation of many microbubbles with iron particles at the edge or outside of the microbubbles. In vivo experiments in mice with MCF-7 tumors demonstrated that Fe3O4/ICG@PLGA/PFP NPs could achieve tumor ablation upon NIR laser irradiation with minimal toxicity to non-irradiated tissues. Together, our results indicate that Fe3O4/ICG@PLGA/PFP NPs can be used as effective nanotheranostic agents for tumor ablation.
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Affiliation(s)
- Chengcheng Niu
- Department of Ultrasound Diagnosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Yan Xu
- Department of Ultrasound Diagnosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Senbo An
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Ming Zhang
- Department of Ultrasound Diagnosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Yihe Hu
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Long Wang
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
| | - Qinghai Peng
- Department of Ultrasound Diagnosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China.
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35
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Feng G, Hao L, Xu C, Ran H, Zheng Y, Li P, Cao Y, Wang Q, Xia J, Wang Z. High-intensity focused ultrasound-triggered nanoscale bubble-generating liposomes for efficient and safe tumor ablation under photoacoustic imaging monitoring. Int J Nanomedicine 2017; 12:4647-4659. [PMID: 28721041 PMCID: PMC5500488 DOI: 10.2147/ijn.s135391] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
High-intensity focused ultrasound (HIFU) is widely applied to tumors in clinical practice due to its minimally invasive approach. However, several issues lower therapeutic efficiency in some cases. Many synergists such as microbubbles and perfluorocarbon nanoparticles have recently been used to improve HIFU treatment efficiency, but none were determined to be effective and safe in vivo. In this study, nanoscale bubble-generating liposomes (liposomes containing ammonium bicarbonate [Lip-ABC]) were prepared by film hydration followed by sequential extrusion. Their stable nanoscale particle diameter was confirmed, and their bubble-generating capacity after HIFU triggering was demonstrated with ultrasound imaging. Lip-ABC had good stability in vivo and accumulated in the tumor interstitial space based on the enhanced permeability and retention effect evaluated by photoacoustic imaging. When used to synergize HIFU ablation to bovine liver in vitro and implanted breast tumors of BALB/c nude mice, Lip-ABC outperformed the control. Importantly, all mice survived HIFU treatment, suggesting that Lip-ABC is a safe HIFU synergist.
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Affiliation(s)
- Gang Feng
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Lan Hao
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Chunyan Xu
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Haitao Ran
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Yuanyi Zheng
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Pan Li
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Yang Cao
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Qi Wang
- State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing, People's Republic of China
| | - Jizhu Xia
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
| | - Zhigang Wang
- Department of Ultrasound, Institute of Ultrasound Imaging, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ultrasound Molecular Imaging
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Niu C, Wang L, Wang Z, Xu Y, Hu Y, Peng Q. Laser irradiated fluorescent perfluorocarbon microparticles in 2-D and 3-D breast cancer cell models. Sci Rep 2017; 7:43408. [PMID: 28262671 PMCID: PMC5338257 DOI: 10.1038/srep43408] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 01/24/2017] [Indexed: 12/20/2022] Open
Abstract
Perfluorocarbon (PFC) droplets were studied as new generation ultrasound contrast agents via acoustic or optical droplet vaporization (ADV or ODV). Little is known about the ODV irradiated vaporization mechanisms of PFC-microparticle complexs and the stability of the new bubbles produced. In this study, fluorescent perfluorohexane (PFH) poly(lactic-co-glycolic acid) (PLGA) particles were used as a model to study the process of particle vaporization and bubble stability following excitation in two-dimensional (2-D) and three-dimensional (3-D) cell models. We observed localization of the fluorescent agent on the microparticle coating material initially and after vaporization under fluorescence microscopy. Furthermore, the stability and growth dynamics of the newly created bubbles were observed for 11 min following vaporization. The particles were co-cultured with 2-D cells to form 3-D spheroids and could be vaporized even when encapsulated within the spheroids via laser irradiation, which provides an effective basis for further work.
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Affiliation(s)
- Chengcheng Niu
- Department of Ultrasound Diagnosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Long Wang
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Zhigang Wang
- Second Affiliated Hospital, Institute of Ultrasound Imaging, Chongqing Medical University, Chongqing, 400010, China
| | - Yan Xu
- Department of Ultrasound Diagnosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Yihe Hu
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Qinghai Peng
- Department of Ultrasound Diagnosis, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
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Ho YJ, Yeh CK. Concurrent anti-vascular therapy and chemotherapy in solid tumors using drug-loaded acoustic nanodroplet vaporization. Acta Biomater 2017; 49:472-485. [PMID: 27836803 DOI: 10.1016/j.actbio.2016.11.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/03/2016] [Accepted: 11/07/2016] [Indexed: 02/08/2023]
Abstract
Drug-loaded nanodroplets (NDs) can be converted into gas bubbles through ultrasound (US) stimulation, termed acoustic droplet vaporization (ADV), which provides a potential strategy to simultaneously induce vascular disruption and release drugs for combined physical anti-vascular therapy and chemotherapy. Doxorubicin-loaded NDs (DOX-NDs) with a mean size of 214nm containing 2.48mg DOX/mL were used in this study. High-speed images displayed bubble formation and cell debris, demonstrating the reduction in cell viability after ADV. Intravital imaging provided direct visualization of disrupted tumor vessels (vessel size <30μm), the extravasation distance was 12μm in the DOX-NDs group and increased over 100μm in the DOX-NDs+US group. Solid tumor perfusion on US imaging was significantly reduced to 23% after DOX-NDs vaporization, but gradually recovered to 41%, especially at the tumor periphery after 24h. Histological images of the DOX-NDs+US group revealed tissue necrosis, a large amount of drug extravasation, vascular disruption, and immune cell infiltration at the tumor center. Tumor sizes decreased 22%, 36%, and 68% for NDs+US, DOX-NDs, and DOX-NDs+US, respectively, to prolong the survival of tumor-bearing mice. Therefore, this study demonstrates that the combination of physical anti-vascular therapy and chemotherapy with DOX-NDs vaporization promotes uniform treatment to improve therapeutic efficacy. STATEMENT OF SIGNIFICANCE Tumor vasculature plays an important role for tumor cell proliferation by transporting oxygen and nutrients. Previous studies combined anti-vascular therapy and drug release to inhibit tumor growth by ultrasound-stimulated microbubble destruction or acoustic droplet vaporization. Although the efficacy of combined therapy has been demonstrated; the relative spatial distribution of vascular disruption, drug delivery, and accompanied immune responses within solid tumors was not discussed clearly. Herein, our study used drug-loaded nanodroplets to combined physical anti-vascular and chemical therapy. The in vitro cytotoxicity, intravital imaging, and histological assessment were used to evaluate the temporal and spatial cooperation between physical and chemical effect. These results revealed some evidences for complementary action to explain the high efficacy of tumor inhibition by combined therapy.
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Rojas JD, Dayton PA. Optimizing Acoustic Activation of Phase Change Contrast Agents With the Activation Pressure Matching Method: A Review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2017; 64:264-272. [PMID: 27740481 PMCID: PMC5270505 DOI: 10.1109/tuffc.2016.2616304] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Submicrometer phase-change contrast agents (PCCAs) consist of a liquid perfluorocarbon (PFC) core that can be vaporized by ultrasound (acoustic droplet vaporization) to generate contrast with excellent spatial and temporal control. When these agents, commonly referred to as nanodroplets, are formulated with cores of low boiling-point PFCs such as decafluorobutane and octafluoropropane, they can be activated with low-mechanical-index (MI) imaging pulses for diagnostic applications. Since the utilization of minimum MI is often desirable to avoid unnecessary biological effects, enabling consistent activation of these agents in an acoustic field is a challenge because the energy that must be delivered to achieve the vaporization threshold increases with depth due to attenuation. A novel vaporization approach called activation pressure matching (APM) has been developed to deliver the same pressure throughout a field of view in order to produce uniform nanodroplet vaporization and to limit the amount of energy that is delivered. In this paper, we discuss the application of this method with a Verasonics V1 Research Ultrasound System to modulate the output pressure from an ATL L11-5 transducer. Vaporization-pulse spacing optimization can be used in addition to matching the activation pressure through depth, and we demonstrate the feasibility of this approach both in vivo and in vitro. The use of optimized vaporization parameters increases the amount of time a single bolus of nanodroplets can generate useful contrast and provides consistent image enhancement in vivo. Therefore, APM is a useful technique for maximizing the efficacy of PCCA while minimizing delivered acoustic energy.
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Ho YJ, Chang YC, Yeh CK. Improving Nanoparticle Penetration in Tumors by Vascular Disruption with Acoustic Droplet Vaporization. Theranostics 2016; 6:392-403. [PMID: 26909113 PMCID: PMC4737725 DOI: 10.7150/thno.13727] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/20/2015] [Indexed: 12/21/2022] Open
Abstract
Drug penetration influences the efficacy of tumor therapy. Although the leaky vessels of tumors can improve the penetration of nanodrugs via the enhanced permeability and retention (EPR) effect, various aspects of the tumor microenvironment still restrict this process. This study investigated whether vascular disruption using the acoustic vaporization of micro- or nanoscale droplets (MDs or NDs) induced by ultrasound sonication can overcome the limitations of the EPR effect to allow drug diffusion into extensive regions. The intravital penetration of DiI-labeled liposomes (as a drug model with red fluorescence) was observed using an acousto-optical integrated system comprising a 2-MHz focused ultrasound transducer (transmitting a three-cycle single pulse and a peak negative pressure of 10 MPa) in a window-chamber mouse model. Histology images of the solid tumor were also used to quantify and demonstrate the locations where DiI-labeled liposomes accumulated. In the intravital image analyses, the cumulative diffusion area and fluorescence intensity at 180 min were 0.08±0.01 mm(2) (mean±standard deviation) and 8.5±0.4%, respectively, in the EPR group, 0.33±0.01 mm(2) and 13.1±0.4% in the MD group (p<0.01), and 0.63±0.01 mm(2) and 18.9±1.1% in the ND group (p<0.01). The intratumoral accumulations of DiI-labeled liposomes were 1.7- and 2.3-fold higher in the MD and ND groups, respectively, than in the EPR group. These results demonstrate that vascular disruption induced by acoustic droplet vaporization can improve drug penetration more than utilizing the EPR effect. The NDs showed longer lifetime in vivo than MDs and provided potential abilities of long periods of treatment, intertissue ND vaporization, and intertissue NDs-converted bubble cavitation to improve the drug penetration and transport distance.
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Seda R, Li DS, Fowlkes JB, Bull JL. Characterization of Bioeffects on Endothelial Cells under Acoustic Droplet Vaporization. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:3241-52. [PMID: 26403698 PMCID: PMC4794981 DOI: 10.1016/j.ultrasmedbio.2015.07.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/19/2015] [Accepted: 07/16/2015] [Indexed: 05/11/2023]
Abstract
Gas embolotherapy is achieved by locally vaporizing microdroplets through acoustic droplet vaporization, which results in bubbles that are large enough to occlude blood flow directed to tumors. Endothelial cells, lining blood vessels, can be affected by these vaporization events, resulting in cell injury and cell death. An idealized monolayer of endothelial cells was subjected to acoustic droplet vaporization using a 3.5-MHz transducer and dodecafluoropentane droplets. Treatments included insonation pressures that varied from 2 to 8 MPa (rarefactional) and pulse lengths that varied from 4 to 16 input cycles. The bubble cloud generated was directly dependent on pressure, but not on pulse length. Cellular damage increased with increasing bubble cloud size, but was limited to the bubble cloud area. These results suggest that vaporization near the endothelium may impact the vessel wall, an effect that could be either deleterious or beneficial depending on the intended overall therapeutic application.
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Affiliation(s)
- Robinson Seda
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - David S Li
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - J Brian Fowlkes
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Joseph L Bull
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.
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Li S, Lin S, Cheng Y, Matsunaga TO, Eckersley RJ, Tang MX. Quantifying activation of perfluorocarbon-based phase-change contrast agents using simultaneous acoustic and optical observation. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:1422-31. [PMID: 25656747 PMCID: PMC5706456 DOI: 10.1016/j.ultrasmedbio.2014.12.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 12/01/2014] [Accepted: 12/15/2014] [Indexed: 05/05/2023]
Abstract
Phase-change contrast agents in the form of nanoscale droplets can be activated into microbubbles by ultrasound, extending the contrast beyond the vasculature. This article describes simultaneous optical and acoustical measurements for quantifying the ultrasound activation of phase-change contrast agents over a range of concentrations. In experiments, decafluorobutane-based nanodroplets of different dilutions were sonicated with a high-pressure activation pulse and two low-pressure interrogation pulses immediately before and after the activation pulse. The differences between the pre- and post-interrogation signals were calculated to quantify the acoustic power scattered by the microbubbles activated over a range of droplet concentrations. Optical observation occurred simultaneously with the acoustic measurement, and the pre- and post-microscopy images were processed to generate an independent quantitative indicator of the activated microbubble concentration. Both optical and acoustic measurements revealed linear relationships to the droplet concentration at a low concentration range <10(8)/mL when measured at body temperature. Further increases in droplet concentration resulted in saturation of the acoustic interrogation signal. Compared with body temperature, room temperature was found to produce much fewer and larger bubbles after ultrasound droplet activation.
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Affiliation(s)
- Sinan Li
- Department of Bioengineering, Imperial College London, London, UK
| | - Shengtao Lin
- Department of Bioengineering, Imperial College London, London, UK
| | - Yi Cheng
- Department of Bioengineering, Imperial College London, London, UK
| | - Terry O Matsunaga
- Department of Medical Imaging, University of Arizona, Tucson, Arizona, USA
| | | | - Meng-Xing Tang
- Department of Bioengineering, Imperial College London, London, UK.
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Sheeran PS, Rojas JD, Puett C, Hjelmquist J, Arena CB, Dayton PA. Contrast-enhanced ultrasound imaging and in vivo circulatory kinetics with low-boiling-point nanoscale phase-change perfluorocarbon agents. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:814-31. [PMID: 25619781 PMCID: PMC5599113 DOI: 10.1016/j.ultrasmedbio.2014.10.020] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 05/03/2023]
Abstract
Many studies have explored phase-change contrast agents (PCCAs) that can be vaporized by an ultrasonic pulse to form microbubbles for ultrasound imaging and therapy. However, few investigations have been published on the utility and characteristics of PCCAs as contrast agents in vivo. In this study, we examine the properties of low-boiling-point nanoscale PCCAs evaluated in vivo and compare data with those for conventional microbubbles with respect to contrast generation and circulation properties. To do this, we develop a custom pulse sequence to vaporize and image PCCAs using the Verasonics research platform and a clinical array transducer. Results indicate that droplets can produce contrast enhancement similar to that of microbubbles (7.29 to 18.24 dB over baseline, depending on formulation) and can be designed to circulate for as much as 3.3 times longer than microbubbles. This study also reports for the first time the ability to capture contrast washout kinetics of the target organ as a measure of vascular perfusion.
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Affiliation(s)
- Paul S Sheeran
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Juan D Rojas
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Connor Puett
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Jordan Hjelmquist
- Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Christopher B Arena
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA.
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Kang ST, Lin YC, Yeh CK. Mechanical bioeffects of acoustic droplet vaporization in vessel-mimicking phantoms. ULTRASONICS SONOCHEMISTRY 2014; 21:1866-74. [PMID: 24690297 DOI: 10.1016/j.ultsonch.2014.03.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/10/2014] [Accepted: 03/10/2014] [Indexed: 05/13/2023]
Abstract
This study investigated the mechanical bioeffects exerted by acoustic droplet vaporization (ADV) under different experimental conditions using vessel phantoms with a 200-μm inner diameter but different stiffness for imitating the microvasculature in various tumors. High-speed microscopy, passive cavitation detection, and ultrasound attenuation measurement were conducted to determine the morphological characteristics of vascular damage and clarify the mechanisms by which the damage was initiated and developed. The results show that phantom erosion was initiated under successive ultrasound exposure (2 MHz, 3 cycles) at above 8-MPa peak negative pressures (PNPs) when ADV occurred with inertial cavitation (IC), producing lesions whose morphological characteristics were dependent on the amount of vaporized droplets. Slight injury occurred at droplet concentrations below (2.6±0.2)×10(6) droplets/mL, forming shallow and rugged surfaces on both sides of the vessel walls. Increasing the droplet concentration to up to (2.6±0.2)×10(7) droplets/mL gradually suppressed the damage on the distal wall, and turned the rugged surface on the proximal wall into tunnels rapidly elongating in the direction opposite to ultrasound propagation. Increasing the PNP did not increase the maximum tunnel depth after the ADV efficiency reached a plateau (about 71.6±2.7% at 10 MPa). Increasing the pulse duration effectively increased the maximum tunnel depth to more than 10 times the diameter of the vessel even though there was no marked enhancement in IC dose. It can be inferred that substantial bubble generation in single ADV events may simultaneously distort the acoustic pressure distribution. The backward ultrasound reinforcement and forward ultrasound shielding relative to the direction of wave propagation augment the propensity of backward erosion. The results of the present work provide information that is valuable for the prevention or utilization of ADV-mediated mechanical bioeffects in clinical applications.
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Affiliation(s)
- Shih-Tsung Kang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Yi-Chen Lin
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Chih-Kuang Yeh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
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Lin CY, Pitt WG. Acoustic droplet vaporization in biology and medicine. BIOMED RESEARCH INTERNATIONAL 2013; 2013:404361. [PMID: 24350267 PMCID: PMC3853706 DOI: 10.1155/2013/404361] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 09/17/2013] [Accepted: 10/03/2013] [Indexed: 01/20/2023]
Abstract
This paper reviews the literature regarding the use of acoustic droplet vaporization (ADV) in clinical applications of imaging, embolic therapy, and therapeutic delivery. ADV is a physical process in which the pressure waves of ultrasound induce a phase transition that causes superheated liquid nanodroplets to form gas bubbles. The bubbles provide ultrasonic imaging contrast and other functions. ADV of perfluoropentane was used extensively in imaging for preclinical trials in the 1990s, but its use declined rapidly with the advent of other imaging agents. In the last decade, ADV was proposed and explored for embolic occlusion therapy, drug delivery, aberration correction, and high intensity focused ultrasound (HIFU) sensitization. Vessel occlusion via ADV has been explored in rodents and dogs and may be approaching clinical use. ADV for drug delivery is still in preclinical stages with initial applications to treat tumors in mice. Other techniques are still in preclinical studies but have potential for clinical use in specialty applications. Overall, ADV has a bright future in clinical application because the small size of nanodroplets greatly reduces the rate of clearance compared to larger contrast agent bubbles and yet provides the advantages of ultrasonographic contrast, acoustic cavitation, and nontoxicity of conventional perfluorocarbon contrast agent bubbles.
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Affiliation(s)
- Chung-Yin Lin
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA
- Department of Neurosurgery, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
- Division of Clinical Toxicology, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
| | - William G. Pitt
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA
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Thakkar D, Gupta R, Monson K, Rapoport N. Effect of ultrasound on the permeability of vascular wall to nano-emulsion droplets. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1804-11. [PMID: 23849384 PMCID: PMC3777764 DOI: 10.1016/j.ultrasmedbio.2013.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 03/08/2013] [Accepted: 04/11/2013] [Indexed: 05/10/2023]
Abstract
The effect of ultrasound on the permeability of blood vessels to nano-emulsion droplets was investigated using excised mouse carotid arteries as model blood vessels. Perfluorocarbon nano-droplets were formed by perfluoro-15-crown-5-ether and stabilized by poly(ethylene oxide)-co-poly(DL-lactide) block co-polymer shells. Nano-droplet fluorescence was imparted by interaction with fluorescein isothiocyanate-dextran (molecular weight = 70,000 Da). The permeability of carotid arteries to nano-droplets was studied in the presence and absence of continuous wave or pulsed therapeutic 1-MHz ultrasound. The data indicated that the application of ultrasound resulted in permeabilization of the vascular wall to nano-droplets. The effect of continuous wave ultrasound was substantially stronger than that of pulsed ultrasound of the same total energy. No effect of blood vessel pre-treatment with ultrasound was observed.
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Affiliation(s)
- Dhaval Thakkar
- Department of Mechanical Engineering, University of Utah, Salt Lake City, Utah 84112, USA
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