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Hampson R, Senior R, Ring L, Robinson S, Augustine DX, Becher H, Anderson N, Willis J, Chandrasekaran B, Kardos A, Siva A, Leeson P, Rana BS, Chahal N, Oxborough D. Contrast echocardiography: a practical guideline from the British Society of Echocardiography. Echo Res Pract 2023; 10:23. [PMID: 37964335 PMCID: PMC10648732 DOI: 10.1186/s44156-023-00034-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/11/2023] [Indexed: 11/16/2023] Open
Abstract
Ultrasound contrast agents (UCAs) have a well-established role in clinical cardiology. Contrast echocardiography has evolved into a routine technique through the establishment of contrast protocols, an excellent safety profile, and clinical guidelines which highlight the incremental prognostic utility of contrast enhanced echocardiography. This document aims to provide practical guidance on the safe and effective use of contrast; reviews the role of individual staff groups; and training requirements to facilitate its routine use in the echocardiography laboratory.
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Affiliation(s)
| | - Roxy Senior
- London North West University Healthcare NHS Trust, London, UK.
- Royal Brompton Hospital and Imperial College, London, UK.
| | - Liam Ring
- West Suffolk Hospital NHS Foundation Trust, Bury St Edmunds, UK
| | | | - Daniel X Augustine
- Royal United Hospitals Bath NHS Foundation Trust, Bath, UK
- Department for, Health University of Bath, Bath, UK
| | - Harald Becher
- Alberta Heart Institute, University of Alberta Hospital, Edmonton, Canada
| | - Natasha Anderson
- Warrington and Halton Teaching Hospital NHS Foundation Trust, Warrington, UK
| | - James Willis
- Royal United Hospitals Bath NHS Foundation Trust, Bath, UK
| | | | - Attila Kardos
- Translational Cardiovascular Research Group, Department of Cardiology, Milton Keynes University Hospital, Milton Keynes, UK
- Faculty of Medicine and Health Sciences, University of Buckingham, Buckingham, UK
| | | | - Paul Leeson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | | | - Navtej Chahal
- London North West University Healthcare NHS Trust, London, UK
| | - David Oxborough
- Liverpool Centre for Cardiovascular Science, Liverpool John Moores University, Liverpool, UK
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Kennedy SR, Lafond M, Haworth KJ, Escudero DS, Ionascu D, Frierson B, Huang S, Klegerman ME, Peng T, McPherson DD, Genstler C, Holland CK. Initiating and imaging cavitation from infused echo contrast agents through the EkoSonic catheter. Sci Rep 2023; 13:6191. [PMID: 37062767 PMCID: PMC10106464 DOI: 10.1038/s41598-023-33164-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 04/07/2023] [Indexed: 04/18/2023] Open
Abstract
Ultrasound-enhanced delivery of therapeutic-loaded echogenic liposomes is under development for vascular applications using the EkoSonic Endovascular System. In this study, fibrin-targeted echogenic liposomes loaded with an anti-inflammatory agent were characterized before and after infusion through an EkoSonic catheter. Cavitation activity was nucleated by Definity or fibrin-targeted, drug-loaded echogenic liposomes infused and insonified with EkoSonic catheters. Passive cavitation imaging was used to quantify and map bubble activity in a flow phantom mimicking porcine arterial flow. Cavitation was sustained during 3-min infusions of Definity or echogenic liposomes along the distal 6 cm treatment zone of the catheter. Though the EkoSonic catheter was not designed specifically for cavitation nucleation, infusion of drug-loaded echogenic liposomes can be employed to trigger and sustain bubble activity for enhanced intravascular drug delivery.
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Affiliation(s)
- Sonya R Kennedy
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cardiovascular Center 3935, 231 Albert Sabin Way, Cincinnati, OH, 45267-0586, USA
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Maxime Lafond
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cardiovascular Center 3935, 231 Albert Sabin Way, Cincinnati, OH, 45267-0586, USA
- LabTAU, Inserm, Université Lyon 1, Lyon, France
| | - Kevin J Haworth
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cardiovascular Center 3935, 231 Albert Sabin Way, Cincinnati, OH, 45267-0586, USA
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Daniel Suarez Escudero
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cardiovascular Center 3935, 231 Albert Sabin Way, Cincinnati, OH, 45267-0586, USA
| | - Dan Ionascu
- Department of Radiation Oncology, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Brion Frierson
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Shaoling Huang
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Melvin E Klegerman
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Tao Peng
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - David D McPherson
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | | | - Christy K Holland
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cardiovascular Center 3935, 231 Albert Sabin Way, Cincinnati, OH, 45267-0586, USA.
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA.
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3
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Microbubbles for human diagnosis and therapy. Biomaterials 2023; 294:122025. [PMID: 36716588 DOI: 10.1016/j.biomaterials.2023.122025] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/17/2023] [Accepted: 01/24/2023] [Indexed: 01/26/2023]
Abstract
Microbubbles (MBs) were observed for the first time in vivo as a curious consequence of quick saline injection during ultrasound (US) imaging of the aortic root, more than 50 years ago. From this serendipitous event, MBs are now widely used as contrast enhancers for US imaging. Their intrinsic properties described in this review, allow a multitude of designs, from shell to gas composition but also from grafting targeting agents to drug payload encapsulation. Indeed, the versatile MBs are deeply studied for their dual potential in imaging and therapy. As presented in this paper, new generations of MBs now opens perspectives for targeted molecular imaging along with the development of new US imaging systems. This review also presents an overview of the different therapeutic strategies with US and MBs for cancer, cardiovascular diseases, and inflammation. The overall aim is to overlap those fields in order to find similarities in the MBs application for treatment enhancement associated with US. To conclude, this review explores the new scales of MBs technologies with nanobubbles development, and along concurrent advances in the US imaging field. This review ends by discussing perspectives for the booming future uses of MBs.
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Kalayeh K, Fowlkes JB, Chen A, Yeras S, Fabiilli ML, Claflin J, Daignault-Newton S, Schultz WW, Sack BS. Pressure Measurement in a Bladder Phantom Using Contrast-Enhanced Ultrasonography-A Path to a Catheter-Free Voiding Cystometrogram. Invest Radiol 2023; 58:181-189. [PMID: 36070543 DOI: 10.1097/rli.0000000000000919] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The long-term goal of this study is to investigate the efficacy of a novel, ultrasound-based technique called subharmonic-aided pressure estimation (SHAPE) to measure bladder pressure as a part of a cystometrogram (CMG) in a urodynamic test (ie, pressure-flow study). SHAPE is based on the principle that subharmonic emissions from ultrasound contrast microbubbles (MBs) decrease linearly with an increase in ambient pressure. We hypothesize that, using the SHAPE technique, we can measure voiding bladder pressure catheter-free. This is of importance because the CMG catheter, due to its space-occupying property and non-physiological effects, can undermine the reliability of the test during voiding and cause misdiagnosis. In this study, we tested this hypothesis and optimized the protocol in a controlled benchtop environment. MATERIALS AND METHODS A bladder phantom was designed and built, capable of simulating clinically relevant bladder pressures. Laboratory-made lipid-shelled MBs (similar in composition to the commercial agent, DEFINITY) was diluted in 0.9% normal saline and infused into the bladder phantom using the CMG infusion system. A typical simulated CMG consists of 1 filling and 4 post-filling events. During CMG events, the bladder phantom is pressurized multiple times at different clinically relevant levels (small, medium, and large) to simulate bladder pressures. Simultaneous with pressurization, MB subharmonic signal was acquired. For each event, the change in MB subharmonic amplitude was correlated linearly with the change in bladder phantom pressure, and the SHAPE conversion factor (slope of the linear fit) was determined. In doing so, a specific signal processing technique (based on a small temporal window) was used to account for time-decay of MB subharmonic signal during a simulated CMG. RESULTS A strong inverse linear relationship was found to exist between SHAPE and bladder phantom pressures for each of the CMG filling and post-filling events ( r2> 0.9, root mean square error < 0.3 dB, standard error <0.01 dB, and P < 0.001). SHAPE showed a transient behavior in measuring bladder phantom pressure. The SHAPE conversion factor (in dB/cm H 2 O) varied between filling and post-filling events, as well as by post-filling time. The magnitude of the SHAPE conversion factor tended to increase immediately after filling and then decreases with time. CONCLUSIONS Microbubble subharmonic emission is an excellent indicator of bladder phantom pressure variation. The strong correlation between SHAPE signal and bladder phantom pressure is indicative of the applicability of this method in measuring bladder pressure during a CMG. Our results suggest that different SHAPE conversion factors may be needed for different events during a CMG (ie, at different time points of a CMG). These findings will help us better protocolize this method for introduction into human subjects and allow us to take the next step toward developing a catheter-free voiding CMG using SHAPE.
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Affiliation(s)
| | | | - Amy Chen
- Department of Biomedical Engineering
| | | | | | | | | | - William W Schultz
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI
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Kalayeh K, Fowlkes JB, Claflin J, Fabiilli ML, Schultz WW, Sack BS. Ultrasound Contrast Stability for Urinary Bladder Pressure Measurement. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:136-151. [PMID: 36244919 DOI: 10.1016/j.ultrasmedbio.2022.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/13/2022] [Accepted: 08/08/2022] [Indexed: 06/16/2023]
Abstract
The goal of this study was to evaluate ultrasound contrast microbubbles (MB) stability during a typical cystometrogram (CMG) for bladder pressure measurement application using the subharmonic-aided pressure estimation technique. A detailed study of MB stability was required given two unique characteristics of this application: first, bulk infusion of MBs into the bladder through the CMG infusion system, and second, duration of a typical CMG which may last up to 30 min. To do so, a series of size measurement and contrast-enhanced ultrasound imaging studies under different conditions were performed and the effects of variables that we hypothesized have an effect on MB stability, namely, i) IV bag air headspace, ii) MB dilution factor, and iii) CMG infusion system were investigated. The results verified that air volume in intravenous (IV) bag headspace was not enough to have a significant effect on MB stability during a CMG. We also showed that higher MB dosage results in a more stable condition. Finally, the results indicated that the CMG infusion system adversely affects MB stability. In summary, to ensure MB stability during the entire duration of a CMG, lower filling rates (limited by estimated bladder capacity in clinical applications) and/or higher MB dosage (limited by FDA regulations and shadowing artifact) and/or the consideration of alternative catheter design may be needed.
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Affiliation(s)
- Kourosh Kalayeh
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - J Brian Fowlkes
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.
| | - Jake Claflin
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mario L Fabiilli
- Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA
| | - William W Schultz
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Bryan S Sack
- Department of Urology, University of Michigan, Ann Arbor, Michigan, USA
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Zalloum IO, Paknahad AA, Kolios MC, Karshafian R, Tsai SSH. Controlled Shrinkage of Microfluidically Generated Microbubbles by Tuning Lipid Concentration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13021-13029. [PMID: 36260341 DOI: 10.1021/acs.langmuir.2c01439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Monodisperse microbubbles with diameters less than 10 μm are desirable in several ultrasound imaging and therapeutic delivery applications. However, conventional approaches to synthesize microbubbles, which are usually agitation-based, produce polydisperse bubbles that are less desirable because of their heterogeneous response when exposed to an ultrasound field. Microfluidics technology has the unique advantage of generating size-controlled monodisperse microbubbles, and it is now well established that the diameter of microfluidically made microbubbles can be tuned by varying the liquid flow rate, gas pressure, and dimensions of the microfluidic channel. It is also observed that once the microbubbles form, the bubbles shrink and eventually stabilize to a quasi-equilibrium diameter, and that the rate of stabilization is related to the lipid solution. However, how the lipid solution concentration affects the degree of bubble shrinkage, and the stable size of microbubbles, has not been thoroughly examined. Here, we investigate whether and how the lipid concentration affects the degree of microbubble shrinkage. Namely, we utilize a flow-focusing microfluidic geometry to generate monodisperse bubbles, and observe the effect of gas composition (2.5, 1.42, and 0.17 wt % octafluoropropane in nitrogen) and lipid concentration (1-16 mg/mL) on the degree of microbubble shrinkage. For the lipid system and gas utilized in these experiments, we observe a monotonic increase in the degree of microbubble shrinkage with decreasing lipid concentration, and no dependency on the gas composition. We hypothesize that the degree of shrinkage is related to lipid concentration by the self-assembly of lipids on the gas-liquid interface during bubble generation and subsequent lipid packing on the interface during shrinkage, which is arrested when a maximum packing density is achieved. We anticipate that this approach for creating and tuning the size of monodisperse microbubbles will find utility in biomedical applications, such as contrast-enhanced ultrasound imaging and ultrasound-triggered gene delivery.
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Affiliation(s)
- Intesar O Zalloum
- Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Ali A Paknahad
- Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Michael C Kolios
- Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Raffi Karshafian
- Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
| | - Scott S H Tsai
- Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, 209 Victoria Street, Toronto, Ontario M5B 1T8, Canada
- Keenan Research Centre for Biomedical Science, Unity Health Toronto, 209 Victoria Street, Toronto, Ontario M5B 1W8, Canada
- Graduate Program in Biomedical Engineering, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada
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7
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Tsivgoulis G, Safouris A, Alexandrov AV. Ultrasonography. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00046-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Tehrani Fateh S, Moradi L, Kohan E, Hamblin MR, Shiralizadeh Dezfuli A. Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:808-862. [PMID: 34476167 PMCID: PMC8372309 DOI: 10.3762/bjnano.12.64] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 07/15/2021] [Indexed: 05/03/2023]
Abstract
The field of theranostics has been rapidly growing in recent years and nanotechnology has played a major role in this growth. Nanomaterials can be constructed to respond to a variety of different stimuli which can be internal (enzyme activity, redox potential, pH changes, temperature changes) or external (light, heat, magnetic fields, ultrasound). Theranostic nanomaterials can respond by producing an imaging signal and/or a therapeutic effect, which frequently involves cell death. Since ultrasound (US) is already well established as a clinical imaging modality, it is attractive to combine it with rationally designed nanoparticles for theranostics. The mechanisms of US interactions include cavitation microbubbles (MBs), acoustic droplet vaporization, acoustic radiation force, localized thermal effects, reactive oxygen species generation, sonoluminescence, and sonoporation. These effects can result in the release of encapsulated drugs or genes at the site of interest as well as cell death and considerable image enhancement. The present review discusses US-responsive theranostic nanomaterials under the following categories: MBs, micelles, liposomes (conventional and echogenic), niosomes, nanoemulsions, polymeric nanoparticles, chitosan nanocapsules, dendrimers, hydrogels, nanogels, gold nanoparticles, titania nanostructures, carbon nanostructures, mesoporous silica nanoparticles, fuel-free nano/micromotors.
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Affiliation(s)
- Sepand Tehrani Fateh
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Lida Moradi
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Elmira Kohan
- Department of Science, University of Kurdistan, Kurdistan, Sanandaj, Iran
| | - Michael R Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein 2028, South Africa
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9
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Krafft MP, Riess JG. Therapeutic oxygen delivery by perfluorocarbon-based colloids. Adv Colloid Interface Sci 2021; 294:102407. [PMID: 34120037 DOI: 10.1016/j.cis.2021.102407] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 03/18/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
After the protocol-related indecisive clinical trial of Oxygent, a perfluorooctylbromide/phospholipid nanoemulsion, in cardiac surgery, that often unduly assigned the observed untoward effects to the product, the development of perfluorocarbon (PFC)-based O2 nanoemulsions ("blood substitutes") has come to a low. Yet, significant further demonstrations of PFC O2-delivery efficacy have continuously been reported, such as relief of hypoxia after myocardial infarction or stroke; protection of vital organs during surgery; potentiation of O2-dependent cancer therapies, including radio-, photodynamic-, chemo- and immunotherapies; regeneration of damaged nerve, bone or cartilage; preservation of organ grafts destined for transplantation; and control of gas supply in tissue engineering and biotechnological productions. PFC colloids capable of augmenting O2 delivery include primarily injectable PFC nanoemulsions, microbubbles and phase-shift nanoemulsions. Careful selection of PFC and other colloid components is critical. The basics of O2 delivery by PFC nanoemulsions will be briefly reminded. Improved knowledge of O2 delivery mechanisms has been acquired. Advanced, size-adjustable O2-delivering nanoemulsions have been designed that have extended room-temperature shelf-stability. Alternate O2 delivery options are being investigated that rely on injectable PFC-stabilized microbubbles or phase-shift PFC nanoemulsions. The latter combine prolonged circulation in the vasculature, capacity for penetrating tumor tissues, and acute responsiveness to ultrasound and other external stimuli. Progress in microbubble and phase-shift emulsion engineering, control of phase-shift activation (vaporization), understanding and control of bubble/ultrasound/tissue interactions is discussed. Control of the phase-shift event and of microbubble size require utmost attention. Further PFC-based colloidal systems, including polymeric micelles, PFC-loaded organic or inorganic nanoparticles and scaffolds, have been devised that also carry substantial amounts of O2. Local, on-demand O2 delivery can be triggered by external stimuli, including focused ultrasound irradiation or tumor microenvironment. PFC colloid functionalization and targeting can help adjust their properties for specific indications, augment their efficacy, improve safety profiles, and expand the range of their indications. Many new medical and biotechnological applications involving fluorinated colloids are being assessed, including in the clinic. Further uses of PFC-based colloidal nanotherapeutics will be briefly mentioned that concern contrast diagnostic imaging, including molecular imaging and immune cell tracking; controlled delivery of therapeutic energy, as for noninvasive surgical ablation and sonothrombolysis; and delivery of drugs and genes, including across the blood-brain barrier. Even when the fluorinated colloids investigated are designed for other purposes than O2 supply, they will inevitably also carry and deliver a certain amount of O2, and may thus be considered for O2 delivery or co-delivery applications. Conversely, O2-carrying PFC nanoemulsions possess by nature a unique aptitude for 19F MR imaging, and hence, cell tracking, while PFC-stabilized microbubbles are ideal resonators for ultrasound contrast imaging and can undergo precise manipulation and on-demand destruction by ultrasound waves, thereby opening multiple theranostic opportunities.
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Affiliation(s)
- Marie Pierre Krafft
- University of Strasbourg, Institut Charles Sadron (CNRS), 23 rue du Loess, 67034 Strasbourg, France.
| | - Jean G Riess
- Harangoutte Institute, 68160 Ste Croix-aux-Mines, France
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10
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Xiaoting ZBS, Zhifei DP. Micro/Nanobubbles Driven Multimodal Imaging and Theragnostics of Cancer. ADVANCED ULTRASOUND IN DIAGNOSIS AND THERAPY 2021. [DOI: 10.37015/audt.2021.200053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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11
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Abstract
Gas-filled microbubbles are currently in clinical use as blood pool contrast agents for ultrasound imaging. The goal of this review is to discuss the trends and issues related to these relatively unusual intravascular materials, which are not small molecules per se, not polymers, not even nanoparticles, but larger micrometer size structures, compressible, flexible, elastic, and deformable. The intent is to connect current research and initial studies from 2 to 3 decades ago, tied to gas exchange between the bubbles and surrounding biological medium, in the following areas of focus: (1) parameters of microbubble movement in relation to vasculature specifics; (2) gas uptake and loss from the bubbles in the vasculature; (3) adhesion of microbubbles to target receptors in the vasculature; and (4) microbubble interaction with the surrounding vessels and tissues during insonation.Microbubbles are generally safe and require orders of magnitude lower material doses than x-ray and magnetic resonance imaging contrast agents. Application of microbubbles will soon extend beyond blood pool contrast and tissue perfusion imaging. Microbubbles can probe molecular and cellular biomarkers of disease by targeted contrast ultrasound imaging. This approach is now in clinical trials, for example, with the aim to detect and delineate tumor nodes in prostate, breast, and ovarian cancer. Imaging of inflammation, ischemia-reperfusion injury, and ischemic memory is also feasible. More importantly, intravascular microbubbles can be used for local deposition of focused ultrasound energy to enhance drug and gene delivery to cells and tissues, across endothelial barrier, especially blood-brain barrier.Overall, microbubble behavior, stability and in vivo lifetime, bioeffects upon the action of ultrasound and resulting enhancement of drug and gene delivery, as well as targeted imaging are critically dependent on the events of gas exchange between the bubbles and surrounding media, as outlined in this review.
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Affiliation(s)
- Alexander L Klibanov
- From the Cardiovascular Division, Department of Medicine and Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine; and Departments of Biomedical Engineering, and Radiology, University of Virginia, Charlottesville, VA
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Abou-Saleh RH, Delaney A, Ingram N, Batchelor DVB, Johnson BRG, Charalambous A, Bushby RJ, Peyman SA, Coletta PL, Markham AF, Evans SD. Freeze-Dried Therapeutic Microbubbles: Stability and Gas Exchange. ACS APPLIED BIO MATERIALS 2020; 3:7840-7848. [DOI: 10.1021/acsabm.0c00982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Radwa H. Abou-Saleh
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
- Biophysics Group, Department of Physics, Faculty of Science, Mansoura University, Mansoura 35511, Egypt
| | - Aileen Delaney
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Nicola Ingram
- Leeds Institute of Medical Research, Wellcome Trust Brenner
Building, St. James’s University Hospital, Leeds LS9 7TF, U.K
| | - Damien V. B. Batchelor
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Benjamin R. G. Johnson
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
| | - Antonia Charalambous
- Leeds Institute of Medical Research, Wellcome Trust Brenner
Building, St. James’s University Hospital, Leeds LS9 7TF, U.K
| | - Richard J. Bushby
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Sally A. Peyman
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
- Leeds Institute of Medical Research, Wellcome Trust Brenner
Building, St. James’s University Hospital, Leeds LS9 7TF, U.K
| | - P. Louise Coletta
- Leeds Institute of Medical Research, Wellcome Trust Brenner
Building, St. James’s University Hospital, Leeds LS9 7TF, U.K
| | - Alexander F. Markham
- Leeds Institute of Medical Research, Wellcome Trust Brenner
Building, St. James’s University Hospital, Leeds LS9 7TF, U.K
| | - Stephen D. Evans
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, U.K
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Xu T, Cui Z, Li D, Cao F, Xu J, Zong Y, Wang S, Bouakaz A, Wan M, Zhang S. Cavitation characteristics of flowing low and high boiling-point perfluorocarbon phase-shift nanodroplets during focused ultrasound exposures. ULTRASONICS SONOCHEMISTRY 2020; 65:105060. [PMID: 32199255 DOI: 10.1016/j.ultsonch.2020.105060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 01/15/2020] [Accepted: 03/07/2020] [Indexed: 06/10/2023]
Abstract
This work investigated and compared the dynamic cavitation characteristics between low and high boiling-point phase-shift nanodroplets (NDs) under physiologically relevant flow conditions during focused ultrasound (FUS) exposures at different peak rarefactional pressures. A passive cavitation detection (PCD) system was used to monitor cavitation activity during FUS exposure at various acoustic pressure levels. Root mean square (RMS) amplitudes of broadband noise, spectrograms of the passive cavitation detection signals, and normalized inertial cavitation dose (ICD) values were calculated. Cavitation activity of low-boiling-point perfluoropentane (PFP) NDs and high boiling-point perfluorohexane (PFH) NDs flowing at in vitro mean velocities of 0-15 cm/s were compared in a 4-mm diameter wall-less vessel in a transparent tissue-mimicking phantom. In the static state, both types of phase-shift NDs exhibit a sharp rise in cavitation intensity during initial FUS exposure. Under flow conditions, cavitation activity of the PFH NDs reached the steady state less rapidly compared to PFP NDs under the lower acoustic pressure (1.35 MPa); at the higher acoustic pressure (1.65 MPa), the RMS amplitude increased more sharply during the initial FUS exposure period. In particular, the RMS-time curves of the PFP NDs shifted upward as the mean flow velocity increased from 0 to 15 cm/s; the RMS amplitude of the PFH ND solution increased from 0 to 10 cm/s and decreased at 15 cm/s. Moreover, amplitudes of the echo signal for the low boiling-point PFP NDs were higher compared to the high boiling-point PFH NDs in the lower frequency range, whereas the inverse occurred in the higher frequency range. Both PFP and PFH NDs showed increased cavitation activity in the higher frequency under the flow condition compared to the static state, especially PFH NDs. At 1.65 MPa, normalized ICD values for PFH increased from 0.93 ± 0.03 to 0.96 ± 0.04 and from 0 to 10 cm/s, then decreased to 0.86 ± 0.05 at 15 cm/s. This work contributes to our further understanding of cavitation characteristics of phase-shift NDs under physiologically relevant flow conditions during FUS exposure. In addition, the results provide a reference for selecting suitable phase-shift NDs to enhance the efficiency of cavitation-mediated ultrasonic applications.
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Affiliation(s)
- Tianqi Xu
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Zhiwei Cui
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Dapeng Li
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Fangyuan Cao
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Jichen Xu
- Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China; National Engineering Laboratory for Visual Information Processing and Applications, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Yujin Zong
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Supin Wang
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | | | - Mingxi Wan
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
| | - Siyuan Zhang
- The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
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14
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Al-Jawadi S, Thakur SS. Ultrasound-responsive lipid microbubbles for drug delivery: A review of preparation techniques to optimise formulation size, stability and drug loading. Int J Pharm 2020; 585:119559. [PMID: 32574685 DOI: 10.1016/j.ijpharm.2020.119559] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/14/2020] [Accepted: 06/15/2020] [Indexed: 02/08/2023]
Abstract
Lipid-shelled microbubbles have received extensive interest to enhance ultrasound-responsive drug delivery outcomes due to their high biocompatibility. While therapeutic effectiveness of microbubbles is well established, there remain limitations in sample homogeneity, stability profile and drug loading properties which restrict these formulations from seeing widespread use in the clinical setting. In this review, we evaluate and discuss the most encouraging leads in lipid microbubble design and optimisation. We examine current applications in drug delivery for the systems and subsequently detail shell compositions and preparation strategies that improve monodispersity while retaining ultrasound responsiveness. We review how excipients and storage techniques help maximise stability and introduce different characterisation and drug loading techniques and evaluate their impact on formulation performance. The review concludes with current quality control measures in place to ensure lipid microbubbles can be reproducibly used in drug delivery.
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Affiliation(s)
- Sana Al-Jawadi
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Sachin S Thakur
- School of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
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15
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Duan L, Yang L, Jin J, Yang F, Liu D, Hu K, Wang Q, Yue Y, Gu N. Micro/nano-bubble-assisted ultrasound to enhance the EPR effect and potential theranostic applications. Theranostics 2020; 10:462-483. [PMID: 31903132 PMCID: PMC6929974 DOI: 10.7150/thno.37593] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 10/11/2019] [Indexed: 12/23/2022] Open
Abstract
Drug delivery for tumor theranostics involves the extensive use of the enhanced permeability and retention (EPR) effect. Previously, various types of nanomedicines have been demonstrated to accumulate in solid tumors via the EPR effect. However, EPR is a highly variable phenomenon because of tumor heterogeneity, resulting in low drug delivery efficacy in clinical trials. Because ultrasonication using micro/nanobubbles as contrast agents can disrupt blood vessels and enhance the specific delivery of drugs, it is an effective approach to improve the EPR effect for the passive targeting of tumors. In this review, the basic thermal effect, acoustic streaming, and cavitation mechanisms of ultrasound, which are characteristics that can be utilized to enhance the EPR effect, are briefly introduced. Second, micro/nanobubble-enhanced ultrasound imaging is discussed to understand the validity and variability of the EPR effect. Third, because the tumor microenvironment is complicated owing to elevated interstitial fluid pressure and the deregulated extracellular matrix components, which may be unfavorable for the EPR effect, few new trends in smart bubble drug delivery systems, which may improve the accuracy of EPR-mediated passive drug targeting, are summarized. Finally, the challenging and major concerns that should be considered in the next generation of micro/nanobubble-contrast-enhanced ultrasound theranostics for EPR-mediated passive drug targeting are also discussed.
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Affiliation(s)
- Lei Duan
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, P. R. China
| | - Li Yang
- State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - Juan Jin
- State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - Fang Yang
- State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - Dong Liu
- West Anhui University, Lu'an, P.R. China
- Anhui Engineering Laboratory for Conservation and Sustainable Utilization of Traditional Chinese Medicine Resources, P. R. China
| | - Ke Hu
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, P. R. China
| | - Qinxin Wang
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, P. R. China
| | - Yuanbin Yue
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, P. R. China
| | - Ning Gu
- School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, 211166, P. R. China
- State Key Laboratory of Bioelectronics, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, P. R. China
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16
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Tabata H, Koyama D, Matsukawa M, Yoshida K, Krafft MP. Vibration Characteristics and Persistence of Poloxamer- or Phospholipid-Coated Single Microbubbles under Ultrasound Irradiation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11322-11329. [PMID: 31419140 DOI: 10.1021/acs.langmuir.9b02006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Microbubbles shelled with soft materials are expected to find applications as ultrasound-sensitive drug delivery systems, including through sonoporation. Microbubbles with specific vibrational characteristics and long intravascular persistence are required for clinical uses. To achieve this aim, the kinetics of the microbubble shell components at the gas/liquid interface while being subjected to ultrasound need to be better understood. This paper investigates the vibration characteristics and lifetime of single microbubbles coated with a poloxamer surfactant, Pluronic F-68, and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) under ultrasound irradiation. Air- and perfluorohexane (PFH)-filled microbubbles coated with Pluronic F-68 and DMPC at several concentrations (0 to 10-2 mol L-1) were produced. An optical measurement system using a laser Doppler vibrometer and microscope was used to observe the radial vibration mode of single microbubbles. The vibrational displacement amplitude and resonance radius of Pluronic- or DMPC-coated microbubbles were found to depend very little on the concentrations. The resonance radius was around 65 μm at 38.8 kHz under all the experimental conditions investigated. The lifetime of the microbubbles was investigated simultaneously by measuring their temporal change in volume, and it was increased with Pluronic concentration. Remarkably, the oscillation amplitude of the bubble has an effect on the bubble lifetime. In other words, larger oscillation under the resonance condition accelerates the diffusion of the inner gas.
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Affiliation(s)
- Hiraku Tabata
- Faculty of Science and Engineering , Doshisha University , 1-3 Tataramiyakodani , Kyotanabe , Kyoto 610-0321 , Japan
| | - Daisuke Koyama
- Faculty of Science and Engineering , Doshisha University , 1-3 Tataramiyakodani , Kyotanabe , Kyoto 610-0321 , Japan
| | - Mami Matsukawa
- Faculty of Science and Engineering , Doshisha University , 1-3 Tataramiyakodani , Kyotanabe , Kyoto 610-0321 , Japan
| | - Kenji Yoshida
- Center for Frontier Medical Engineering , Chiba University , 1-33 Yayoicho , Inage-ku , Chiba 263-8522 , Japan
| | - Marie Pierre Krafft
- Institut Charles Sadron (CNRS) , University of Strasbourg , 23 rue du Loess , 67034 Strasbourg , France
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17
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Newsome IG, Kierski TM, Dayton PA. Assessment of the Superharmonic Response of Microbubble Contrast Agents for Acoustic Angiography as a Function of Microbubble Parameters. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:2515-2524. [PMID: 31174922 PMCID: PMC7202402 DOI: 10.1016/j.ultrasmedbio.2019.04.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 05/07/2023]
Abstract
Acoustic angiography is a superharmonic contrast-enhanced ultrasound imaging technique that enables 3-D high-resolution microvascular visualization. This technique utilizes a dual-frequency imaging strategy, transmitting at a low frequency and receiving at a higher frequency, to detect high-frequency contrast agent signatures and separate them from tissue background. Prior studies have illustrated differences in microbubble scatter dependent on microbubble size and composition; however, most previously reported data have utilized a relatively narrow frequency bandwidth centered around the excitation frequency. To date, a comprehensive study of isolated microbubble superharmonic responses with a broadband dual-frequency system has not been performed. Here, the superharmonic signal production of 14 contrast agents with various gas cores, shell compositions, and bubble diameters at mechanical indices of 0.2 to 1.2 was evaluated using a transmit 4 MHz, receive 25 MHz configuration. Results indicate that perfluorocarbon cores or lipid shells with 18- or 20-carbon acyl chains produce more superharmonic signal than sulfur hexafluoride cores or lipid shells with 16-carbon acyl chains, respectively. As microbubble diameter increases from 1 to 4 µm, superharmonic generation decreases. In a comparison of two clinical agents, Definity and Optison, and one preclinical agent, Micromarker, Optison produced the least superharmonic signal. Overall, this work suggests that microbubbles around 1 μm in diameter with perfluorocarbon cores and longer-chained lipid shells perform best for superharmonic imaging at 4 MHz. Studies have found that microbubble superharmonic response follows trends different from those described in prior studies using a narrower frequency bandwidth centered around the excitation frequency. Future work will apply these results in vivo to optimize the sensitivity of acoustic angiography.
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Affiliation(s)
- Isabel G Newsome
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Thomas M Kierski
- 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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18
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Shi D, Liu X, Counil C, Krafft MP. Fluorocarbon Exposure Mode Markedly Affects Phospholipid Monolayer Behavior at the Gas/Liquid Interface: Impact on Size and Stability of Microbubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10025-10033. [PMID: 30548072 DOI: 10.1021/acs.langmuir.8b03546] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Although most phospholipid-shelled microbubbles (MBs) investigated for medical applications are stabilized by a fluorocarbon (FC) gas, information on the interactions between the phospholipid and FC molecules at the gas/water interface remains scarce. We report that the procedure of introduction of perfluorohexane (F-hexane), that is, either in the gas phase above dimyristoylphosphatidylcholine (DMPC) or dipalmitoylphosphatidylcholine (DPPC) Langmuir monolayers, or in the aqueous subphase, radically affects the compression isotherms. When introduced in the gas phase, F-hexane is rapidly incorporated in the interfacial film, but is also readily desorbed upon compression and eventually totally expelled from the phospholipid monolayers. By contrast, when introduced in the aqueous phase, F-hexane remains trapped at the interface. These dissimilar outcomes demonstrate that the phospholipid monolayer acts as a barrier that effectively hinders the transfer of the FC across the interfacial film. F-hexane was also found to significantly accelerate the adsorption kinetics of the phospholipids at the gas/water interface and to lower the interfacial tension, as assessed by bubble profile analysis tensiometry. The extent of these effects is more pronounced when F-hexane is provided from the gas phase. The size and stability characteristics of DMPC- and DPPC-shelled microbubbles were also found to depend on how the FC is introduced. As compared to reference MBs prepared under nitrogen only, introduction of F-hexane always causes a decrease in MB mean radius. However, while for DMPC this decrease depends on the F-hexane introduction procedure, it is independent from the procedure and most pronounced (from ∼2.0 μm to ∼1.0 μm) for DPPC. Introducing the FC in the gas phase has the strongest effect on MB half-life (t1/2 = ∼1.8 and 6.8 h for DMPC and DPPC, respectively), as compared to when it is delivered through the aqueous phase (∼0.8 and ∼1.7 h). Fluorocarbonless reference DMPC and DPPC bubbles had a half-life of ∼0.5 and 0.8 h, respectively. The effects of F-hexane on MB characteristics are discussed with regard to the interactions between phospholipids and F-hexane and monolayer fluidization effect, as revealed by the Langmuir and tensiometric studies.
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Affiliation(s)
- Da Shi
- University of Strasbourg , Institut Charles Sadron (CNRS) , 23 rue du Loess , 67034 Strasbourg , Cedex , France
| | - Xianhe Liu
- University of Strasbourg , Institut Charles Sadron (CNRS) , 23 rue du Loess , 67034 Strasbourg , Cedex , France
| | - Claire Counil
- University of Strasbourg , Institut Charles Sadron (CNRS) , 23 rue du Loess , 67034 Strasbourg , Cedex , France
| | - Marie Pierre Krafft
- University of Strasbourg , Institut Charles Sadron (CNRS) , 23 rue du Loess , 67034 Strasbourg , Cedex , France
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19
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Abou-Saleh RH, McLaughlan JR, Bushby RJ, Johnson BR, Freear S, Evans SD, Thomson NH. Molecular Effects of Glycerol on Lipid Monolayers at the Gas-Liquid Interface: Impact on Microbubble Physical and Mechanical Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10097-10105. [PMID: 30901226 DOI: 10.1021/acs.langmuir.8b04130] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The production and stability of microbubbles (MBs) is enhanced by increasing the viscosity of both the formation and storage solution, respectively. Glycerol is a good candidate for biomedical applications of MBs, since it is biocompatible, although the exact molecular mechanisms of its action is not fully understood. Here, we investigate the influence glycerol has on lipid-shelled MB properties, using a range of techniques. Population lifetime and single bubble stability were studied using optical microscopy. Bubble stiffness measured by AFM compression is compared with lipid monolayer behavior in a Langmuir-Blodgett trough. We deduce that increasing glycerol concentrations enhances stability of MB populations through a 3-fold mechanism. First, binding of glycerol to lipid headgroups in the interfacial monolayer up to 10% glycerol increases MB stiffness but has limited impact on shell resistance to gas permeation and corresponding MB lifetime. Second, increased solution viscosity above 10% glycerol slows down the kinetics of gas transfer, markedly increasing MB stability. Third, above 10%, glycerol induces water structuring around the lipid monolayer, forming a glassy layer which also increases MB stiffness and resistance to gas loss. At 30% glycerol, the glassy layer is ablated, lowering the MB stiffness, but MB stability is further augmented. Although the molecular interactions of glycerol with the lipid monolayer modulate the MB lipid shell properties, MB lifetime continually increases from 0 to 30% glycerol, indicating that its viscosity is the dominant effect on MB solution stability. This three-fold action and biocompatibility makes glycerol ideal for therapeutic MB formation and storage and gives new insight into the action of glycerol on lipid monolayers at the gas-liquid interface.
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Affiliation(s)
- Radwa H Abou-Saleh
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy , University of Leeds , Leeds LS2 9JT , United Kingdom
- Biophysics Group, Department of Physics, Faculty of Science , Mansoura University , Mansoura , Egypt
| | - James R McLaughlan
- School of Electronic and Electrical Engineering , University of Leeds , Leeds LS2 9JT , United Kingdom
- Leeds Institute of Medical Research , University of Leeds, St. James's University Hospital , Leeds LS9 7TF , United Kingdom
| | - Richard J Bushby
- School of Chemistry , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Benjamin R Johnson
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Steven Freear
- School of Electronic and Electrical Engineering , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Stephen D Evans
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Neil H Thomson
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy , University of Leeds , Leeds LS2 9JT , United Kingdom
- Division of Oral Biology, School of Dentistry , University of Leeds , Leeds LS2 9LU , United Kingdom
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20
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Shekhar H, Palaniappan A, Peng T, Lafond M, Moody MR, Haworth KJ, Huang S, McPherson DD, Holland CK. Characterization and Imaging of Lipid-Shelled Microbubbles for Ultrasound-Triggered Release of Xenon. Neurotherapeutics 2019; 16:878-890. [PMID: 31020629 PMCID: PMC6694347 DOI: 10.1007/s13311-019-00733-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Xenon (Xe) is a bioactive gas capable of reducing and stabilizing neurologic injury in stroke. The goal of this work was to develop lipid-shelled microbubbles for xenon loading and ultrasound-triggered release. Microbubbles loaded with either xenon (Xe-MB) or xenon and octafluoropropane (Xe-OFP-MB) (9:1 v/v) were synthesized by high-shear mixing. The size distribution and the frequency-dependent attenuation coefficient of Xe-MB and Xe-OFP-MB were measured using a Coulter counter and a broadband acoustic attenuation spectroscopy system, respectively. The Xe dose was evaluated using gas chromatography/mass spectrometry. The total Xe doses in Xe-MB and Xe-OFP-MB were 113.1 ± 13.5 and 145.6 ± 25.5 μl per mg of lipid, respectively. Co-encapsulation of OFP increased the total xenon dose, attenuation coefficient, microbubble stability (in an undersaturated solution), and shelf life of the agent. Triggered release of gas payload was demonstrated with 6-MHz duplex Doppler and 220-kHz pulsed ultrasound. These results constitute the first step toward the use of lipid-shelled microbubbles for applications such as neuroprotection in stroke.
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Affiliation(s)
- Himanshu Shekhar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
| | - Arunkumar Palaniappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Tao Peng
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Maxime Lafond
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Melanie R Moody
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Kevin J Haworth
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
| | - Shaoling Huang
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - David D McPherson
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Christy K Holland
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
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21
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Yarmoska SK, Yoon H, Emelianov SY. Lipid Shell Composition Plays a Critical Role in the Stable Size Reduction of Perfluorocarbon Nanodroplets. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1489-1499. [PMID: 30975536 PMCID: PMC6491255 DOI: 10.1016/j.ultrasmedbio.2019.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 02/04/2019] [Accepted: 02/07/2019] [Indexed: 05/20/2023]
Abstract
Perfluorocarbon nanodroplets (PFCnDs) are phase-change contrast agents that have the potential to enable extravascular contrast-enhanced ultrasound and photoacoustic (US/PA) imaging. Producing consistently small, monodisperse PFCnDs remains a challenge without resorting to technically challenging methods. We investigated the impact of variable shell composition on PFCnD size and US/PA image properties. Our results suggest that increasing the molar percentage of PEGylated lipid reduces the size and size variance of PFCnDs. Furthermore, our imaging studies revealed that nanodroplets with more PEGylated lipids produce increased US/PA signal compared with those with the standard formulation. Finally, we highlight the ability of this approach to facilitate US/PA imaging in a murine model of breast cancer. These data indicate that, through a facile synthesis process, it is possible to produce monodisperse, small-sized PFCnDs. Novel in their simplicity, these methods may promote the use of PFCnDs among a broader user base to study a variety of extravascular phenomena.
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Affiliation(s)
- Steven K Yarmoska
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, Georgia, USA
| | - Heechul Yoon
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Stanislav Y Emelianov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, Georgia, USA; School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA.
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22
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Shi D, Wallyn J, Nguyen DV, Perton F, Felder-Flesch D, Bégin-Colin S, Maaloum M, Krafft MP. Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2019; 10:2103-2115. [PMID: 31728258 PMCID: PMC6839566 DOI: 10.3762/bjnano.10.205] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/02/2019] [Indexed: 05/20/2023]
Abstract
Dendrons fitted with three oligo(ethylene glycol) (OEG) chains, one of which contains a fluorinated or hydrogenated end group and bears a bisphosphonate polar head (C n X2 n +1OEG8Den, X = F or H; n = 2 or 4), were synthesized and grafted on the surface of iron oxide nanoparticles (IONPs) for microbubble-mediated imaging and therapeutic purposes. The size and stability of the dendronized IONPs (IONP@C n X2 n +1OEG8Den) in aqueous dispersions were monitored by dynamic light scattering. The investigation of the spontaneous adsorption of IONP@C n X2 n +1OEG8Den at the interface between air or air saturated with perfluorohexane and an aqueous phase establishes that exposure to the fluorocarbon gas markedly increases the rate of adsorption of the dendronized IONPs to the gas/water interface and decreases the equilibrium interfacial tension. This suggests that fluorous interactions are at play between the supernatant fluorocarbon gas and the fluorinated end groups of the dendrons. Furthermore, small perfluorohexane-stabilized microbubbles (MBs) with a dipalmitoylphosphatidylcholine (DPPC) shell that incorporates IONP@C n X2 n +1OEG8Den (DPPC/Fe molar ratio 28:1) were prepared and subsequently characterized using both optical microscopy and an acoustical method of size determination. The dendrons fitted with fluorinated end groups lead to smaller and more stable MBs than those fitted with hydrogenated groups. The most effective result is already obtained with C2F5, for which MBs of ≈1.0 μm in radius reach a half-life of ≈6.0 h. An atomic force microscopy investigation of spin-coated mixed films of DPPC/IONP@C2X5OEG8Den combinations (molar ratio 28:1) shows that the IONPs grafted with the fluorinated dendrons are located within the phospholipid film, while those grafted with the hydrocarbon dendrons are located at the surface of the phospholipid film.
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Affiliation(s)
- Da Shi
- Institut Charles Sadron (CNRS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
| | - Justine Wallyn
- Institut Charles Sadron (CNRS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
| | - Dinh-Vu Nguyen
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
| | - Francis Perton
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
| | - Delphine Felder-Flesch
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
| | - Sylvie Bégin-Colin
- Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
| | - Mounir Maaloum
- Institut Charles Sadron (CNRS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
| | - Marie Pierre Krafft
- Institut Charles Sadron (CNRS), University of Strasbourg, 23 rue du Loess, 67034 Strasbourg, France
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23
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Petrassi FA, Davis JT, Beasley KM, Evero O, Elliott JE, Goodman RD, Futral JE, Subudhi A, Solano-Altamirano JM, Goldman S, Roach RC, Lovering AT. AltitudeOmics: effect of reduced barometric pressure on detection of intrapulmonary shunt, pulmonary gas exchange efficiency, and total pulmonary resistance. J Appl Physiol (1985) 2018; 124:1363-1376. [PMID: 29357511 PMCID: PMC6008081 DOI: 10.1152/japplphysiol.00474.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 12/06/2017] [Accepted: 12/10/2017] [Indexed: 11/22/2022] Open
Abstract
Blood flow through intrapulmonary arteriovenous anastomoses (QIPAVA) occurs in healthy humans at rest and during exercise when breathing hypoxic gas mixtures at sea level and may be a source of right-to-left shunt. However, at high altitudes, QIPAVA is reduced compared with sea level, as detected using transthoracic saline contrast echocardiography (TTSCE). It remains unknown whether the reduction in QIPAVA (i.e., lower bubble scores) at high altitude is due to a reduction in bubble stability resulting from the lower barometric pressure (PB) or represents an actual reduction in QIPAVA. To this end, QIPAVA, pulmonary artery systolic pressure (PASP), cardiac output (QT), and the alveolar-to-arterial oxygen difference (AaDO2) were assessed at rest and during exercise (70-190 W) in the field (5,260 m) and in the laboratory (1,668 m) during four conditions: normobaric normoxia (NN; [Formula: see text] = 121 mmHg, PB = 625 mmHg; n = 8), normobaric hypoxia (NH; [Formula: see text] = 76 mmHg, PB = 625 mmHg; n = 7), hypobaric normoxia (HN; [Formula: see text] = 121 mmHg, PB = 410 mmHg; n = 8), and hypobaric hypoxia (HH; [Formula: see text] = 75 mmHg, PB = 410 mmHg; n = 7). We hypothesized QIPAVA would be reduced during exercise in isooxic hypobaria compared with normobaria and that the AaDO2 would be reduced in isooxic hypobaria compared with normobaria. Bubble scores were greater in normobaric conditions, but the AaDO2 was similar in both isooxic hypobaria and normobaria. Total pulmonary resistance (PASP/QT) was elevated in HN and HH. Using mathematical modeling, we found no effect of hypobaria on bubble dissolution time within the pulmonary transit times under consideration (<5 s). Consequently, our data suggest an effect of hypobaria alone on pulmonary blood flow. NEW & NOTEWORTHY Blood flow through intrapulmonary arteriovenous anastomoses, detected by transthoracic saline contrast echocardiography, was reduced during exercise in acute hypobaria compared with normobaria, independent of oxygen tension, whereas pulmonary gas exchange efficiency was unaffected. Modeling the effect(s) of reduced air density on contrast bubble lifetime did not result in a significantly reduced contrast stability. Interestingly, total pulmonary resistance was increased by hypobaria, independent of oxygen tension, suggesting that pulmonary blood flow may be changed by hypobaria.
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Affiliation(s)
- Frank A Petrassi
- Department of Kinesiology, Recreation, and Sport, Indiana State University, Terre Haute, Indiana
| | - James T Davis
- Department of Kinesiology, Recreation, and Sport, Indiana State University, Terre Haute, Indiana
| | - Kara M Beasley
- Department of Kinesiology, Recreation, and Sport, Indiana State University, Terre Haute, Indiana
| | - Oghenero Evero
- Altitude Research Center, Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus , Denver, Colorado
| | - Jonathan E Elliott
- Department of Kinesiology, Recreation, and Sport, Indiana State University, Terre Haute, Indiana
| | - Randall D Goodman
- Oregon Heart and Vascular Institute, Echocardiography, Springfield, Oregon
| | - Joel E Futral
- Oregon Heart and Vascular Institute, Echocardiography, Springfield, Oregon
| | - Andrew Subudhi
- Altitude Research Center, Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus , Denver, Colorado
| | | | - Saul Goldman
- Department of Chemistry, University of Guelph , Guelph, Ontario , Canada
| | - Robert C Roach
- Altitude Research Center, Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus , Denver, Colorado
| | - Andrew T Lovering
- Department of Kinesiology, Recreation, and Sport, Indiana State University, Terre Haute, Indiana
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24
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Shekhar H, Smith NJ, Raymond JL, Holland CK. Effect of Temperature on the Size Distribution, Shell Properties, and Stability of Definity ®. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:434-446. [PMID: 29174045 PMCID: PMC5759968 DOI: 10.1016/j.ultrasmedbio.2017.09.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 09/28/2017] [Accepted: 09/29/2017] [Indexed: 05/08/2023]
Abstract
Physical characterization of an ultrasound contrast agent (UCA) aids in its safe and effective use in diagnostic and therapeutic applications. The goal of this study was to investigate the impact of temperature on the size distribution, shell properties, and stability of Definity®, a U.S. Food and Drug Administration-approved UCA used for left ventricular opacification. A Coulter counter was modified to enable particle size measurements at physiologic temperatures. The broadband acoustic attenuation spectrum and size distribution of Definity® were measured at room temperature (25 °C) and physiologic temperature (37 °C) and were used to estimate the viscoelastic shell properties of the agent at both temperatures. Attenuation and size distribution was measured over time to assess the effect of temperature on the temporal stability of Definity®. The attenuation coefficient of Definity® at 37 °C was as much as 5 dB higher than the attenuation coefficient measured at 25 °C. However, the size distributions of Definity® at 25 °C and 37 °C were similar. The estimated shell stiffness and viscosity decreased from 1.76 ± 0.18 N/m and 0.21 × 10-6 ± 0.07 × 10-6 kg/s at 25 °C to 1.01 ± 0.07 N/m and 0.04 × 10-6 ± 0.04 × 10-6 kg/s at 37 °C, respectively. Size-dependent differences in dissolution rates were observed within the UCA population at both 25 °C and 37 °C. Additionally, cooling the diluted UCA suspension from 37 °C to 25 °C accelerated the dissolution rate. These results indicate that although temperature affects the shell properties of Definity® and can influence the stability of Definity®, the size distribution of this agent is not affected by a temperature increase from 25 °C to 37 °C.
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Affiliation(s)
- Himanshu Shekhar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA.
| | - Nathaniel J Smith
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jason L Raymond
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - Christy K Holland
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio, USA
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25
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Zullino S, Argenziano M, Stura I, Guiot C, Cavalli R. From Micro- to Nano-Multifunctional Theranostic Platform: Effective Ultrasound Imaging Is Not Just a Matter of Scale. Mol Imaging 2018; 17:1536012118778216. [PMID: 30213222 PMCID: PMC6144578 DOI: 10.1177/1536012118778216] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/20/2018] [Accepted: 04/08/2018] [Indexed: 12/20/2022] Open
Abstract
Ultrasound Contrast Agents (UCAs) consisting of gas-filled-coated Microbubbles (MBs) with diameters between 1 and 10 µm have been used for a number of decades in diagnostic imaging. In recent years, submicron contrast agents have proven to be a viable alternative to MBs for ultrasound (US)-based applications for their capability to extravasate and accumulate in the tumor tissue via the enhanced permeability and retention effect. After a short overview of the more recent approaches to ultrasound-mediated imaging and therapeutics at the nanoscale, phase-change contrast agents (PCCAs), which can be phase-transitioned into highly echogenic MBs by means of US, are here presented. The phenomenon of acoustic droplet vaporization (ADV) to produce bubbles is widely investigated for both imaging and therapeutic applications to develop promising theranostic platforms.
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Affiliation(s)
- Sara Zullino
- Department of Neuroscience, University of Turin, Turin, Italy
| | - Monica Argenziano
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Ilaria Stura
- Department of Clinical and Biological Science, University of Turin, Turin, Italy
| | - Caterina Guiot
- Department of Neuroscience, University of Turin, Turin, Italy
| | - Roberta Cavalli
- Department of Drug Science and Technology, University of Turin, Turin, Italy
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26
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Lin F, Tsuruta JK, Rojas JD, Dayton PA. Optimizing Sensitivity of Ultrasound Contrast-Enhanced Super-Resolution Imaging by Tailoring Size Distribution of Microbubble Contrast Agent. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:2488-2493. [PMID: 28668636 PMCID: PMC8330409 DOI: 10.1016/j.ultrasmedbio.2017.05.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/01/2017] [Accepted: 05/08/2017] [Indexed: 05/03/2023]
Abstract
Ultrasound contrast-enhanced super-resolution imaging has recently attracted attention because of its extraordinary ability to image vascular features much smaller than the ultrasound diffraction limit. This method requires sensitive detection of separable microbubble events despite a noisy tissue background to indicate the microvasculature, and any approach that could improve the sensitivity of the ultrasound system to individual microbubbles would be highly beneficial. In this study, we evaluated the effect of varying microbubble size on super-resolution imaging sensitivity. Microbubble preparations were size sorted into different mean diameters and then were imaged at equal concentrations. Commercially manufactured Definity and Optison were also imaged for comparison. Both in vitro experiments in phantom vessels and in vivo experiments imaging rat tumors revealed that the sensitivity of contrast-enhanced super-resolution imaging can be improved by using microbubbles with a larger diameter.
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Affiliation(s)
- Fanglue Lin
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - James K Tsuruta
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Juan D Rojas
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA.
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27
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Shekhar H, Bader KB, Huang S, Peng T, Huang S, McPherson DD, Holland CK. In vitro thrombolytic efficacy of echogenic liposomes loaded with tissue plasminogen activator and octafluoropropane gas. Phys Med Biol 2016; 62:517-538. [PMID: 28002053 DOI: 10.1088/1361-6560/62/2/517] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Echogenic liposomes loaded with the thrombolytic recombinant tissue-type plasminogen activator (rt-PA) are under development for the treatment of ischemic stroke. These agents are designed to co-encapsulate cavitation nuclei to promote bubble activity in response to ultrasound exposure, and to enable localized delivery of thrombolytic. Stable cavitation improves the efficacy of the thrombolytic through enhanced fluid mixing. Echogenic liposomes that encapsulate air-filled microbubbles nucleate scant stable cavitation activity in response to 120 kHz intermittent ultrasound exposure, and have demonstrated thrombolytic efficacy equivalent to rt-PA alone. It was hypothesized that encapsulating octafluoropropane (OFP) gas within rt-PA-loaded liposomes instead of air will enhance ultrasound-mediated stable cavitation activity and increase thrombolytic efficacy compared to previous studies. The thrombolytic efficacy and cavitation activity nucleated from liposomes that encapsulate OFP microbubbles and rt-PA (OFP t-ELIP) was evaluated in vitro. Human whole blood clots were exposed to human fresh-frozen plasma alone, rt-PA (0, 0.32, 1.58, and 3.15 µg ml-1), or OFP t-ELIP at equivalent enzymatic activity, with and without exposure to intermittent ultrasound. Further, numerical simulations were performed to gain insight into the mechanisms of cavitation nucleation. Sustained ultraharmonic activity was nucleated from OFP t-ELIP when exposed to ultrasound. Furthermore, the thrombolytic efficacy was enhanced compared to rt-PA alone at concentrations of 1.58 µg ml-1 and 3.15 µg ml-1 (p < 0.05). These results indicate that OFP t-ELIP can nucleate sustained stable cavitation activity and enhance the efficacy of thrombolysis.
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Affiliation(s)
- Himanshu Shekhar
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH, USA
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28
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Ando Y, Tabata H, Sanchez M, Cagna A, Koyama D, Krafft MP. Microbubbles with a Self-Assembled Poloxamer Shell and a Fluorocarbon Inner Gas. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:12461-12467. [PMID: 27409141 DOI: 10.1021/acs.langmuir.6b01883] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The numerous applications of microbubbles in food science and medicine call for a better understanding and control of the effects of the properties of their shells on their stability and ability to resonate at chosen frequencies when submitted to an ultrasound field. We have investigated both millimetric and micrometric bubbles stabilized by an amphiphilic block copolymer, Poloxamer 188 (e.g., Pluronic F-68). Although Pluronic F-68 is routinely being used as a dispersing and foaming agent to facilitate phospholipid-based microbubble preparation, it has never been studied as a shell component per se. First, we investigated the adsorption kinetics of Pluronic F-68 at the interface between water and air, or air saturated with vapors of perfluorohexane (F-hexane), using bubble profile tensiometry analysis. F-Hexane was found to strongly accelerate the adsorption of Pluronic F-68 (at low concentrations) and decrease the interfacial tension values at equilibrium (at all concentrations). We also found that relatively stable microbubbles could unexpectedly be prepared from Pluronic F-68 in the absence of any other surfactant, but only when F-hexane was present. These bubbles showed an only limited volume increase over ∼3 h, while a 10-fold increase in size occurred within 200 s in the absence of a fluorocarbon. Remarkably, their deflation rate decreased when the Pluronic F-68 concentration decreased, suggesting that bubbles with semidilute copolymer coverage are more stable than those more densely covered by copolymer brushes. Single-bubble experiments using laser Doppler vibratometry showed that, by contrast with other surfactant-coated microbubbles, the resonance radius of the Pluronic F-68-coated microbubbles was lower than that of naked microbubbles, meaning that they are less elastic. It was also found that the bubble's vibrational displacement amplitude decreased substantially when the microbubbles were covered with Pluronic F-68, an effect that was further amplified by F-hexane.
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Affiliation(s)
- Yu Ando
- Faculty of Life and Medical Sciences, Doshisha University , Kyoto 610-0321, Japan
- Institut Charles Sadron (CNRS), University of Strasbourg , 23 rue du Loess, 67034 Strasbourg, France
| | - Hiraku Tabata
- Faculty of Life and Medical Sciences, Doshisha University , Kyoto 610-0321, Japan
- Institut Charles Sadron (CNRS), University of Strasbourg , 23 rue du Loess, 67034 Strasbourg, France
| | | | - Alain Cagna
- TECLIS Instruments , Tassin, 69160 Lyon Métropole, France
| | - Daisuke Koyama
- Faculty of Life and Medical Sciences, Doshisha University , Kyoto 610-0321, Japan
| | - Marie Pierre Krafft
- Institut Charles Sadron (CNRS), University of Strasbourg , 23 rue du Loess, 67034 Strasbourg, France
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29
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Raymond JL, Luan Y, Peng T, Huang SL, McPherson DD, Versluis M, de Jong N, Holland CK. Loss of gas from echogenic liposomes exposed to pulsed ultrasound. Phys Med Biol 2016; 61:8321-8339. [PMID: 27811382 DOI: 10.1088/0031-9155/61/23/8321] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The destruction of echogenic liposomes (ELIP) in response to pulsed ultrasound excitations has been studied acoustically previously. However, the mechanism underlying the loss of echogenicity due to cavitation nucleated by ELIP has not been fully clarified. In this study, an ultra-high speed imaging approach was employed to observe the destruction phenomena of single ELIP exposed to ultrasound bursts at a center frequency of 6 MHz. We observed a rapid size reduction during the ultrasound excitation in 139 out of 397 (35%) ultra- high-speed recordings. The shell dilation rate, which is defined as the microbubble wall velocity divided by the instantaneous radius, [Formula: see text] /R, was extracted from the radius versus time response of each ELIP, and was found to be correlated with the deflation. Fragmentation and surface mode vibrations were also observed and are shown to depend on the applied acoustic pressure and initial radius. Results from this study can be utilized to optimize the theranostic application of ELIP, e.g. by tuning the size distribution or the excitation frequency.
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Affiliation(s)
- Jason L Raymond
- Biomedical Engineering Program, University of Cincinnati, Cardiovascular Center 3940, 231 Albert Sabin Way, Cincinnati, OH 45267-0586, USA
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30
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Affiliation(s)
- Yuqi Zhang
- Joint
Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27695, United States
- Center
for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics,
UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department
of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jicheng Yu
- Joint
Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27695, United States
- Center
for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics,
UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Hunter N. Bomba
- Joint
Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Yong Zhu
- Joint
Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27695, United States
- Department
of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Zhen Gu
- Joint
Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, North Carolina 27695, United States
- Center
for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics,
UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department
of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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31
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Abou-Saleh RH, Peyman SA, Johnson BRG, Marston G, Ingram N, Bushby R, Coletta PL, Markham AF, Evans SD. The influence of intercalating perfluorohexane into lipid shells on nano and microbubble stability. SOFT MATTER 2016; 12:7223-30. [PMID: 27501364 DOI: 10.1039/c6sm00956e] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Microbubbles are potential diagnostic and therapeutic agents. In vivo stability is important as the bubbles are required to survive multiple passages through the heart and lungs to allow targeting and delivery. Here we have systematically varied key parameters affecting microbubble lifetime to significantly increase in vivo stability. Whilst shell and core composition are found to have an important role in improving microbubble stability, we show that inclusion of small quantities of C6F14 in the microbubble bolus significantly improves microbubble lifetime. Our results indicate that C6F14 inserts into the lipid shell, decreasing surface tension to 19 mN m(-1), and increasing shell resistance, in addition to saturating the surrounding medium. Surface area isotherms suggest that C6F14 incorporates into the acyl chain region of the lipid at a high molar ratio, indicating ∼2 perfluorocarbon molecules per 5 lipid molecules. The resulting microbubble boluses exhibit a higher in vivo image intensity compared to commercial compositions, as well as longer lifetimes.
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Affiliation(s)
- Radwa H Abou-Saleh
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, LS2 9JT, UK.
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32
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Hackett HK, Boulet LM, Dominelli PB, Foster GE. A methodological approach for quantifying and characterizing the stability of agitated saline contrast: implications for quantifying intrapulmonary shunt. J Appl Physiol (1985) 2016; 121:568-76. [PMID: 27365283 DOI: 10.1152/japplphysiol.00422.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 06/27/2016] [Indexed: 12/26/2022] Open
Abstract
Agitated saline contrast echocardiography is often used to determine blood flow through intrapulmonary arteriovenous anastomoses (Q̇IPAVA). We applied indicator dilution theory to time-acoustic intensity curves obtained from a bolus injection of hand-agitated saline contrast to acquire a quantitative index of contrast mass. Using this methodology and an in vitro model of the pulmonary circulation, the purpose of this study was to determine the effect of transit time and gas composition [air vs. sulphur hexafluoride (SF6)] on contrast conservation between two detection sites separated by a convoluted network of vessels. We hypothesized that the contrast lost between the detection sites would increase with transit times and be reduced by using contrast bubbles composed of SF6 Changing the flow and/or reducing the volume of the circulatory network manipulated transit time. Contrast conservation was measured as the ratio of outflow and inflow contrast masses. For air, 53.2 ± 3.4% (SE) of contrast was conserved at a transit time of 9.25 ± 0.02 s but dropped to 16.0 ± 1.0% at a transit time of 10.17 ± 0.06 s. Compared with air, SF6 contrast conservation was significantly greater (P < 0.05) with 114.3 ± 2.9% and 73.7 ± 3.3% of contrast conserved at a transit time of 10.39 ± 0.02 s and 13.46 ± 0.04 s, respectively. In summary, time-acoustic intensity curves can quantify agitated saline contrast, but loss of contrast due to bubble dissolution makes measuring Q̇IPAVA across varying transit time difficult. Agitated saline composed of SF6 is stabilized and may be a suitable alternative for Q̇IPAVA measurement.
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Affiliation(s)
- Heather K Hackett
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada; and
| | - Lindsey M Boulet
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada; and
| | - Paolo B Dominelli
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Glen E Foster
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada; and
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33
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Huynh E, Rajora MA, Zheng G. Multimodal micro, nano, and size conversion ultrasound agents for imaging and therapy. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2016; 8:796-813. [PMID: 27006001 DOI: 10.1002/wnan.1398] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 01/30/2016] [Accepted: 02/02/2016] [Indexed: 12/20/2022]
Abstract
Ultrasound (US) is one of the most commonly used clinical imaging techniques. However, the use of US and US-based intravenous agents extends far beyond imaging. In particular, there has been a surge in the fabrication of multimodality US contrast agents and theranostic US agents for cancer imaging and therapy. The unique interaction of US waves with microscale and nanoscale agents has attracted much attention in the development of contrast agents and drug-delivery vehicles. The dimensions of the agent not only dictate how it behaves in vivo, but also how it interacts with US for imaging and drug delivery. Furthermore, these agents are also unique due to their ability to convert from the nanoscale to the microscale and vice versa, having imaging and therapeutic utility in both dimensions. Here, we review multimodality and multifunctional US-based agents, according to their size, and also highlight recent developments in size conversion US agents. WIREs Nanomed Nanobiotechnol 2016, 8:796-813. doi: 10.1002/wnan.1398 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Elizabeth Huynh
- Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Maneesha A Rajora
- Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Gang Zheng
- Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario, Canada. .,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada. .,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.
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34
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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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35
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Meng M, Gao J, Wu C, Zhou X, Zang X, Lin X, Liu H, Wang C, Su H, Liu K, Wang Y, Xue X, Wu J. Doxorubicin nanobubble for combining ultrasonography and targeted chemotherapy of rabbit with VX2 liver tumor. Tumour Biol 2016; 37:8673-80. [PMID: 26738862 PMCID: PMC4990606 DOI: 10.1007/s13277-015-4525-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 11/26/2015] [Indexed: 01/11/2023] Open
Abstract
A new class of multifunctional nanobubble using poly(lactic-co-glycolic acid) (PLGA) has been developed as ultrasound imaging contrast agents, doxorubicin carriers, and enhancers of ultrasound-mediated drug delivery. The doxorubicin nanobubble (DOX-NB) wrapping carbon tetrafluoride gas was prepared with double emulsion method. We evaluated the enhanced ultrasonic function of the DOX-NB in vivo; its antitumor function was confirmed. The diameter of the prepared bubble was 500 nm, and the potential was −23 mV. The drug loading and encapsulation efficiency of the bubble were 78.6 and 7.4 %, respectively. Therefore, the DOX-NB greatly enhanced ultrasound imaging in vivo. Ultrasound combined with DOX-NB had significant antitumor effect. Compared with other groups, the tumor growth rate and the proliferation index were the lowest while the survival rate and apoptosis index were the highest.
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Affiliation(s)
- Mingming Meng
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China
| | - Jie Gao
- The Department of Pathology, Chinese PLA General Hospital, Beijing, China
| | - Chongchong Wu
- The Department of Radiology, Chinese PLA General Hospital, Beijing, China
| | - Xuan Zhou
- The Department of Critical Care Medicine, Chinese PLA General Hospital, Beijing, China
| | - Xuefeng Zang
- The Department of Critical Care Medicine, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Xiangchun Lin
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China
| | - Hong Liu
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China
| | - Canghai Wang
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China
| | - Hui Su
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China
| | - Kuiliang Liu
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China
| | - Yadan Wang
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China
| | - Xinying Xue
- The Department of Special Medical Treatment, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China.
| | - Jing Wu
- The Department of Gastroenterology, Beijing Shijitan Hospital, Capital Medical University, 10 Tieyi Road, Yangfang District, Beijing, 100038, China.
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36
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Haršány M, Tsivgoulis G, Alexandrov AV. Ultrasonography. Stroke 2016. [DOI: 10.1016/b978-0-323-29544-4.00046-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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37
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Huynh E, Leung BYC, Helfield BL, Shakiba M, Gandier JA, Jin CS, Master ER, Wilson BC, Goertz DE, Zheng G. In situ conversion of porphyrin microbubbles to nanoparticles for multimodality imaging. NATURE NANOTECHNOLOGY 2015; 10:325-32. [PMID: 25822929 DOI: 10.1038/nnano.2015.25] [Citation(s) in RCA: 258] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 01/29/2015] [Indexed: 05/08/2023]
Abstract
Converting nanoparticles or monomeric compounds into larger supramolecular structures by endogenous or external stimuli is increasingly popular because these materials are useful for imaging and treating diseases. However, conversion of microstructures to nanostructures is less common. Here, we show the conversion of microbubbles to nanoparticles using low-frequency ultrasound. The microbubble consists of a bacteriochlorophyll-lipid shell around a perfluoropropane gas. The encapsulated gas provides ultrasound imaging contrast and the porphyrins in the shell confer photoacoustic and fluorescent properties. On exposure to ultrasound, the microbubbles burst and form smaller nanoparticles that possess the same optical properties as the original microbubble. We show that this conversion is possible in tumour-bearing mice and could be validated using photoacoustic imaging. With this conversion, our microbubble can potentially be used to bypass the enhanced permeability and retention effect when delivering drugs to tumours.
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Affiliation(s)
- Elizabeth Huynh
- 1] Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario M5G 2M9, Canada [2] Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Ben Y C Leung
- Sunnybrook Health Sciences Center, Toronto, Ontario M4N 3M5, Canada
| | - Brandon L Helfield
- 1] Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada [2] Sunnybrook Health Sciences Center, Toronto, Ontario M4N 3M5, Canada
| | - Mojdeh Shakiba
- 1] Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario M5G 2M9, Canada [2] Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Julie-Anne Gandier
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Cheng S Jin
- 1] Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario M5G 2M9, Canada [2] Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada [3] Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Emma R Master
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Brian C Wilson
- 1] Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario M5G 2M9, Canada [2] Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - David E Goertz
- 1] Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada [2] Sunnybrook Health Sciences Center, Toronto, Ontario M4N 3M5, Canada
| | - Gang Zheng
- 1] Princess Margaret Cancer Center and Techna Institute, University Health Network, Toronto, Ontario M5G 2M9, Canada [2] Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada [3] Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada [4] Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5G 1L7, Canada
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38
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Cavalli R, Argenziano M, Vigna E, Giustetto P, Torres E, Aime S, Terreno E. Preparation and in vitro characterization of chitosan nanobubbles as theranostic agents. Colloids Surf B Biointerfaces 2015; 129:39-46. [PMID: 25819364 DOI: 10.1016/j.colsurfb.2015.03.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 01/21/2015] [Accepted: 03/08/2015] [Indexed: 12/21/2022]
Abstract
Theranostic delivery systems are nanostructures that combine the modality of therapy and diagnostic imaging. Polymeric micro- and nanobubbles, spherical vesicles containing a gas core, have been proposed as new theranostic carriers for MRI-guided therapy. In this study, chitosan nanobubbles were purposely tuned for the co-delivery of prednisolone phosphate and a Gd(III) complex, as therapeutic and MRI diagnostic agent, respectively. Perfluoropentane was used for filling up the internal core of the formulation. These theranostic nanobubbles showed diameters of about 500nm and a positive surface charge that allows the interaction with the negatively charged Gd-DOTP complex. Pluronic F68 was added to the nanobubble aqueous suspension as stabilizer agent. The encapsulation efficiency was good for both the active compounds, and a prolonged drug release profile was observed in vitro. The effect of ultrasound stimulation on prednisolone phosphate release was evaluated at 37°C. A marked increase on drug release kinetics with no burst effect was obtained after the exposure of the system to ultrasound. Furthermore, the relaxivity of the MRI probe changed upon incorporation in the nanobubble shell, thereby offering interesting opportunity in dual MRI-US experiments. The ultrasound characterization showed a good in vitro echogenicity of the theranostic nanobubbles. In summary, chitosan drug-loaded nanobubbles with Gd(III) complex bound to their shell might be considered a new platform for imaging and drug delivery with the potential of improving anti-cancer treatments.
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Affiliation(s)
- R Cavalli
- Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, via P. Giuria 9, 10125 Torino, Italy.
| | - M Argenziano
- Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, via P. Giuria 9, 10125 Torino, Italy
| | - E Vigna
- Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, via P. Giuria 9, 10125 Torino, Italy
| | - P Giustetto
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Centro di Imaging Molecolare e Preclinico, Università degli Studi di Torino, via Nizza 52, 10126 Torino, Italy
| | - E Torres
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Centro di Imaging Molecolare e Preclinico, Università degli Studi di Torino, via Nizza 52, 10126 Torino, Italy
| | - S Aime
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Centro di Imaging Molecolare e Preclinico, Università degli Studi di Torino, via Nizza 52, 10126 Torino, Italy
| | - E Terreno
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Centro di Imaging Molecolare e Preclinico, Università degli Studi di Torino, via Nizza 52, 10126 Torino, Italy.
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39
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Perfluoroalkylated poly(oxyethylene) thiols: Synthesis, adsorption dynamics and surface activity at the air/water interface, and bubble stabilization behaviour. J Fluor Chem 2015. [DOI: 10.1016/j.jfluchem.2014.10.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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40
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Krafft MP. Perfluoroalkyl chains as tools for film surface nano-patterning and soft microbubble engineering and decoration. J Taiwan Inst Chem Eng 2014. [DOI: 10.1016/j.jtice.2014.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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41
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Luan Y, Lajoinie G, Gelderblom E, Skachkov I, van der Steen AFW, Vos HJ, Versluis M, De Jong N. Lipid shedding from single oscillating microbubbles. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:1834-46. [PMID: 24798388 DOI: 10.1016/j.ultrasmedbio.2014.02.031] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 02/11/2014] [Accepted: 02/25/2014] [Indexed: 05/23/2023]
Abstract
Lipid-coated microbubbles are used clinically as contrast agents for ultrasound imaging and are being developed for a variety of therapeutic applications. The lipid encapsulation and shedding of the lipids by acoustic driving of the microbubble has a crucial role in microbubble stability and in ultrasound-triggered drug delivery; however, little is known about the dynamics of lipid shedding under ultrasound excitation. Here we describe a study that optically characterized the lipid shedding behavior of individual microbubbles on a time scale of nanoseconds to microseconds. A single ultrasound burst of 20 to 1000 cycles, with a frequency of 1 MHz and an acoustic pressure varying from 50 to 425 kPa, was applied. In the first step, high-speed fluorescence imaging was performed at 150,000 frames per second to capture the instantaneous dynamics of lipid shedding. Lipid detachment was observed within the first few cycles of ultrasound. Subsequently, the detached lipids were transported by the surrounding flow field, either parallel to the focal plane (in-plane shedding) or in a trajectory perpendicular to the focal plane (out-of-plane shedding). In the second step, the onset of lipid shedding was studied as a function of the acoustic driving parameters, for example, pressure, number of cycles, bubble size and oscillation amplitude. The latter was recorded with an ultrafast framing camera running at 10 million frames per second. A threshold for lipid shedding under ultrasound excitation was found for a relative bubble oscillation amplitude >30%. Lipid shedding was found to be reproducible, indicating that the shedding event can be controlled.
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Affiliation(s)
- Ying Luan
- Biomedical Engineering Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands.
| | - Guillaume Lajoinie
- Physics of Fluids Group and MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Erik Gelderblom
- Physics of Fluids Group and MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Ilya Skachkov
- Biomedical Engineering Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Antonius F W van der Steen
- Biomedical Engineering Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands; Acoustical Wavefield Imaging, Delft University of Technology, Delft, The Netherlands
| | - Hendrik J Vos
- Biomedical Engineering Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands; Acoustical Wavefield Imaging, Delft University of Technology, Delft, The Netherlands
| | - Michel Versluis
- Physics of Fluids Group and MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Nico De Jong
- Biomedical Engineering Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands; Acoustical Wavefield Imaging, Delft University of Technology, Delft, The Netherlands
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42
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Kang ST, Huang YL, Yeh CK. Characterization of acoustic droplet vaporization for control of bubble generation under flow conditions. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:551-61. [PMID: 24433748 DOI: 10.1016/j.ultrasmedbio.2013.10.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 10/20/2013] [Accepted: 10/21/2013] [Indexed: 05/14/2023]
Abstract
This study investigated the manipulation of bubbles generated by acoustic droplet vaporization (ADV) under clinically relevant flow conditions. Optical microscopy and high-frequency ultrasound imaging were used to observe bubbles generated by 2-MHz ultrasound pulses at different time points after the onset of ADV. The dependence of the bubble population on droplet concentration, flow velocity, fluid viscosity and acoustic parameters, including acoustic pressure, pulse duration and pulse repetition frequency, was investigated. The results indicated that post-ADV bubble growth spontaneously driven by air permeation markedly affected the bubble population after insonation. The bubbles can grow to a stable equilibrium diameter as great as twice the original diameter in 0.5-1 s, as predicted by the theoretical calculation. The growth trend is independent of flow velocity, but dependent on fluid viscosity and droplet concentration, which directly influence the rate of gas uptake by bubbles and the rate of gas exchange across the wall of the semipermeable tube containing the bubbles and, hence, the gas content of the host medium. Varying the acoustic pressure does not markedly change the formation of bubbles as long as the ADV thresholds of most droplets are reached. Varying pulse duration and pulse repetition frequency markedly reduces the number of bubbles. Lengthening pulse duration favors the production of large bubbles, but reduces the total number of bubbles. Increasing the PRF interestingly provides superior performance in bubble disruption. These results also suggest that an ADV bubble population cannot be assessed simply on the basis of initial droplet size or enhancement of imaging contrast by the bubbles. Determining the optimal acoustic parameters requires careful consideration of their impact on the bubble population produced for different application scenarios.
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Affiliation(s)
- Shih-Tsung Kang
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Yi-Luan Huang
- 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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43
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Cavalli R, Bisazza A, Lembo D. Micro- and nanobubbles: a versatile non-viral platform for gene delivery. Int J Pharm 2013; 456:437-45. [PMID: 24008081 DOI: 10.1016/j.ijpharm.2013.08.041] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 08/20/2013] [Accepted: 08/24/2013] [Indexed: 01/01/2023]
Abstract
Micro- and nanobubbles provide a promising non-viral strategy for ultrasound mediated gene delivery. Microbubbles are spherical gas-filled structures with a mean diameter of 1-8 μm, characterised by their core-shell composition and their ability to circulate in the bloodstream following intravenous injection. They undergo volumetric oscillations or acoustic cavitation when insonified by ultrasound and, most importantly, they are able to resonate at diagnostic frequencies. It is due to this behaviour that microbubbles are currently being used as ultrasound contrast agents, but their use in therapeutics is still under investigation. For example, microbubbles could play a role in enhancing gene delivery to cells: when combined with clinical ultrasound exposure, microbubbles are able to favour gene entry into cells by cavitation. Two different delivery strategies have been used to date: DNA can be co-administered with the microbubbles (i.e. the contrast agent) or 'loaded' in purposed-built bubble systems - indeed a number of different technological approaches have been proposed to associate genes within microbubble structures. Nanobubbles, bubbles with sizes in the nanometre order of magnitude, have also been developed with the aim of obtaining more efficient gene delivery systems. Their small sizes allow the possibility of extravasation from blood vessels into the surrounding tissues and ultrasound-targeted site-specific release with minimal invasiveness. In contrast, microbubbles, due to their larger sizes, are unable to extravasate, thus and their targeting capacity is limited to specific antigens present within the vascular lumen. This review provides an overview of the use of microbubbles as gene delivery systems, with a specific focus on recent research into the development of nanosystems. In particular, ultrasound delivery mechanisms, formulation parameters, gene-loading approaches and the advantages of nanometric systems will be described.
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Affiliation(s)
- Roberta Cavalli
- Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Via Pietro Giuria 9, 10125 Torino, Italy.
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44
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Helfield BL, Cherin E, Foster FS, Goertz DE. The effect of binding on the subharmonic emissions from individual lipid-encapsulated microbubbles at transmit frequencies of 11 and 25 MHz. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:345-359. [PMID: 23219039 DOI: 10.1016/j.ultrasmedbio.2012.09.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/12/2012] [Accepted: 09/13/2012] [Indexed: 06/01/2023]
Abstract
Targeted microbubble imaging at ultrasound frequencies above 5 MHz has applications in both a preclinical context for a range of disease processes and clinically for the assessment of atherosclerosis and superficial tumors. Although the feasibility of ultrasound molecular imaging has been well demonstrated for a range of target molecules, little work has examined the effects of binding on microbubble oscillations, which is of potential relevance to improving the sensitivity, specificity, and quantification of bound-bubble detection. In this study we investigated the influence of binding on the subharmonic response of bubbles at transmit frequencies of 11 and 25 MHz. Individual bubbles were situated adjacent to a boundary in either a bound or an unbound state, optically sized and acoustically interrogated with pressures ranging from 0.02 to 1.2 MPa. At 11 MHz, unbound bubbles (n = 53) were found to have strong subharmonic activity for sizes between 2.4 and 2.6 μm, whereas bound bubbles (n = 50) were most active from 2.6 to 3.0 μm. Destruction thresholds were found to be lower for bound bubbles. At 25 MHz, bound-bubble (n = 57) activity was found to peak at 1.9 μm as compared to 2.1 μm in the unbound cases (n = 53), with a 20% increase in amplitude. Comparison with simulations indicates that both unbound and bound bubbles undergo compression-only behavior at 11 MHz, and expansion-dominated behavior at 25 MHz. Subharmonic emissions elicited from 0 radian transmit pulses were found to be π/2 radians out of phase with those elicited from a π radian transmit pulse, suggesting inefficient subharmonic preservation from pulse inversion schemes. With the appropriate postprocessed phase correction, an increase in the subharmonic amplitude of up to 60% was shown, depending on the bubble size and transmit frequency.
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Affiliation(s)
- Brandon L Helfield
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
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46
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Nguyen PN, Nikolova G, Polavarapu P, Waton G, Phuoc LT, Pourroy G, Krafft MP. Compressible multi-scale magnetic constructs: decorating the outer surface of self-assembled microbubbles with iron oxide nanoparticles. RSC Adv 2013. [DOI: 10.1039/c3ra40908b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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47
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Benchimol MJ, Hsu MJ, Schutt CE, Hall DJ, Mattrey RF, Esener SC. Phospholipid/Carbocyanine Dye-Shelled Microbubbles as Ultrasound-Modulated Fluorescent Contrast Agents. SOFT MATTER 2013; 9:2384-2388. [PMID: 23526919 PMCID: PMC3601761 DOI: 10.1039/c2sm26900g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Fluorescent microbubbles have been fabricated with the capacity to have their emission modulated by ultrasound. These contrast agent particles could potentially be used in the future to extract fluorescence modulation from a strong light background to increase imaging depth and resolution in scattering media. Fluorescence intensity modulation was demonstrated at the ultrasound driving frequency.
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Affiliation(s)
- Michael J. Benchimol
- Department of Electrical & Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Mark J. Hsu
- Department of Electrical & Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Carolyn E. Schutt
- Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - David J. Hall
- Department of Radiology, University of California at San Diego, Moores Cancer Center, 3855 Health Sciences Drive, La Jolla, California 92093, USA
| | - Robert F. Mattrey
- Department of Radiology, University of California at San Diego, Moores Cancer Center, 3855 Health Sciences Drive, La Jolla, California 92093, USA
| | - Sadik C. Esener
- Department of Electrical & Computer Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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48
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Kwan JJ, Borden MA. Lipid monolayer collapse and microbubble stability. Adv Colloid Interface Sci 2012; 183-184:82-99. [PMID: 22959721 DOI: 10.1016/j.cis.2012.08.005] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 08/10/2012] [Accepted: 08/10/2012] [Indexed: 12/16/2022]
Abstract
Microbubbles are micrometer-size gaseous particles suspended in water, and they are often stabilized by a lipid monolayer shell. Natural microbubbles are found in freshwater and saltwater systems, and engineered microbubbles have a variety of applications in food sciences, biotechnology and medicine. Lipid-coated microbubbles are found to have remarkable stability and mechanical behavior owing to the resistance of the lipid monolayer encapsulation to collapse. The purpose of this review is to tie in recent observations of lipid-coated microbubble dissolution and gas exchange with current literature on the physics of lipid monolayer collapse in the context of lung surfactant. Based on this analysis, we conclude that microbubble shells collapse through the nucleation of microscopic folds, which then catalyze the formation and aggregation of new folds, leading to macroscopic folding events. This process results in a cyclic behavior of crumple-to-smooth transitions, which can be modulated through lipid composition. Eventually, the microbubbles stabilize at 1-2 μm diameter, regardless of initial size or lipid composition, and various mechanisms for this stabilization are postulated. Our ultimate goal is to inspire the reader to consider lipid monolayer collapse as the main long-term stabilizing mechanism for lipid-coated microbubbles, and to stimulate the use of microbubbles as a platform for studying monolayer collapse phenomena.
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Radhakrishnan K, Haworth KJ, Huang SL, Klegerman ME, McPherson DD, Holland CK. Stability of echogenic liposomes as a blood pool ultrasound contrast agent in a physiologic flow phantom. ULTRASOUND IN MEDICINE & BIOLOGY 2012; 38:1970-81. [PMID: 22929652 PMCID: PMC4919816 DOI: 10.1016/j.ultrasmedbio.2012.06.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 06/19/2012] [Accepted: 06/28/2012] [Indexed: 05/09/2023]
Abstract
Echogenic liposomes (ELIP) are multifunctional ultrasound contrast agents (UCAs) with a lipid shell encapsulating both air and an aqueous core. ELIP are being developed for molecular imaging and image-guided therapeutic delivery. Stability of the echogenicity of ELIP in physiologic conditions is crucial to their successful translation to clinical use. In this study, we determined the effects of the surrounding media's dissolved air concentration, temperature transition and hydrodynamic pressure on the echogenicity of a chemically modified formulation of ELIP to promote stability and echogenicity. ELIP samples were diluted in porcine plasma or whole blood and pumped through a pulsatile flow system with adjustable hydrodynamic pressures and temperature. B-mode images were acquired using a clinical diagnostic scanner every 5 s for a total duration of 75 s. Echogenicity in porcine plasma was assessed as a function of total dissolved gas saturation. ELIP were added to plasma at room temperature (22 °C) or body temperature (37 °C) and pumped through a system maintained at 22 °C or 37 °C to study the effect of temperature transitions on ELIP echogenicity. Echogenicity at normotensive (120/80 mmHg) and hypertensive pressures (145/90 mmHg) was measured. ELIP were echogenic in plasma and whole blood at body temperature under normotensive to hypertensive pressures. Warming of samples from room temperature to body temperature did not alter echogenicity. However, in plasma cooled rapidly from body temperature to room temperature or in degassed plasma, ELIP lost echogenicity within 20 s at 120/80 mmHg. The stability of echogenicity of a modified ELIP formulation was determined in vitro at body temperature, physiologic gas concentration and throughout the physiologic pressure range. However, proper care should be taken to ensure that ELIP are not cooled rapidly from body temperature to room temperature as they will lose their echogenic properties. Further in vivo investigations will be needed to evaluate the optimal usage of ELIP as blood pool contrast agents.
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Affiliation(s)
- Kirthi Radhakrishnan
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267-0586, USA.
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50
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Optimization of Acoustic Liposomes for Improved In Vitro and In Vivo Stability. Pharm Res 2012; 30:218-24. [DOI: 10.1007/s11095-012-0864-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 08/13/2012] [Indexed: 10/27/2022]
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