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Singh R, Yang X. A review on photo-mediated ultrasound therapy. Exp Biol Med (Maywood) 2023; 248:775-786. [PMID: 37452726 PMCID: PMC10468643 DOI: 10.1177/15353702231181191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
Photo-mediated ultrasound therapy (PUT) is a novel therapeutic technique based on the combination of ultrasound and laser. The underlying mechanism of PUT is the enhanced cavitation effect inside blood vessels. The enhanced cavitation activity can result in bio-effects such as reduced perfusion in microvessels. The reduced perfusion effect in microvessels in the eye has the potential to control the progression of eye diseases such as diabetic retinopathy and age-related macular degeneration. Several in vivo studies have demonstrated the feasibility of PUT in removing microvasculature in the eye using rabbit eye model and vasculature in the skin using rabbit ear model. Numerical studies using a bubble dynamics model found that cavitation is enhanced during PUT due to the dramatic increase in size of air/vapor nuclei in blood. In addition, the study conducted to model cavitation dynamics inside a blood vessel during PUT found stresses induced on the vessel wall during PUT are higher than that at normal physiological levels, which may be responsible for bio-effects. The concentration of vasodilators such as nitric oxide and prostacyclin were also found to be affected during PUT in an in vitro study, which may limit blood perfusion in vessels. The main advantage of PUT over conventional techniques is non-invasive, precise, and selective removal of microvessels with high efficiency at relatively low energy levels of ultrasound and laser, without affecting the nearby structures. However, the main limitation of vessel rupture/hemorrhage needs to be overcome through the development of real-time monitoring of treatment effects during PUT. In addition to the application in removing microvessels, PUT-based techniques were also explored in treating other diseases. Studies have found a combination of ultrasound and laser to be effective in removing blood clots inside veins, which has the potential to treat deep-vein thrombosis. The disruption of atherosclerotic plaque using combined ultrasound and laser was also tested, and the feasibility was demonstrated.
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Affiliation(s)
- Rohit Singh
- Department of Mechanical Engineering, Institute for Bioengineering Research, The University of Kansas, Lawrence, KS 66045, USA
| | - Xinmai Yang
- Department of Mechanical Engineering, Institute for Bioengineering Research, The University of Kansas, Lawrence, KS 66045, USA
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Qin Y, Geng X, Sun Y, Zhao Y, Chai W, Wang X, Wang P. Ultrasound nanotheranostics: Toward precision medicine. J Control Release 2023; 353:105-124. [PMID: 36400289 DOI: 10.1016/j.jconrel.2022.11.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/24/2022]
Abstract
Ultrasound (US) is a mechanical wave that can penetrate biological tissues and trigger complex bioeffects. The mechanisms of US in different diagnosis and treatment are different, and the functional application of commercial US is also expanding. In particular, recent developments in nanotechnology have led to a wider use of US in precision medicine. In this review, we focus on US in combination with versatile micro and nanoparticles (NPs)/nanovesicles for tumor theranostics. We first introduce US-assisted drug delivery as a stimulus-responsive approach that spatiotemporally regulates the deposit of nanomedicines in target tissues. Multiple functionalized NPs and their US-regulated drug-release curves are analyzed in detail. Moreover, as a typical representative of US therapy, sonodynamic antitumor strategy is attracting researchers' attention. The collaborative efficiency and mechanisms of US and various nano-sensitizers such as nano-porphyrins and organic/inorganic nanosized sensitizers are outlined in this paper. A series of physicochemical processes during ultrasonic cavitation and NPs activation are also discussed. Finally, the new applications of US and diagnostic NPs in tumor-monitoring and image-guided combined therapy are summarized. Diagnostic NPs contain substances with imaging properties that enhance US contrast and photoacoustic imaging. The development of such high-resolution, low-background US-based imaging methods has contributed to modern precision medicine. It is expected that the integration of non-invasive US and nanotechnology will lead to significant breakthroughs in future clinical applications.
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Affiliation(s)
- Yang Qin
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Xiaorui Geng
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Yue Sun
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Yitong Zhao
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Wenyu Chai
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Xiaobing Wang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China.
| | - Pan Wang
- National Engineering Laboratory for Resource Development of Endangered Crude Drugs in Northwest China, The Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry, The Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710119, China.
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Wang Y, Cong H, Wang S, Yu B, Shen Y. Development and application of ultrasound contrast agents in biomedicine. J Mater Chem B 2021; 9:7633-7661. [PMID: 34586124 DOI: 10.1039/d1tb00850a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
With the rapid development of molecular imaging, ultrasound (US) medicine has evolved from traditional imaging diagnosis to integrated diagnosis and treatment at the molecular level. Ultrasound contrast agents (UCAs) play a crucial role in the integration of US diagnosis and treatment. As the micro-bubbles (MBs) in UCAs can enhance the cavitation effect and promote the biological effect of US, UCAs have also been studied in the fields of US thrombolysis, mediated gene transfer, drug delivery, and high intensity focused US. The application range of UCAs is expanding, and the value of their applications is improving. This paper reviews the development and application of UCAs in biomedicine in recent years, and the existing problems and prospects are pointed out.
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Affiliation(s)
- Yu Wang
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Building D, Science Park, Qingdao 266071, China.
| | - Hailin Cong
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Building D, Science Park, Qingdao 266071, China. .,State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China
| | - Song Wang
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Building D, Science Park, Qingdao 266071, China.
| | - Bing Yu
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Building D, Science Park, Qingdao 266071, China. .,State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao 266071, China
| | - Youqing Shen
- Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Affiliated Hospital of Qingdao University, Qingdao University, Building D, Science Park, Qingdao 266071, China. .,Center for Bionanoengineering and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
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Makey IA, Das NA, Jacob S, El-Sayed Ahmed MM, Makey CM, Johnson SB, Thomas M. Agitation Techniques to Enhance Drainage of Retained Hemothorax. Surg Innov 2020; 28:544-551. [PMID: 33339490 DOI: 10.1177/1553350620978002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background. Retained hemothorax (RH) is a common problem in cardiothoracic and trauma surgery. We aimed to determine the optimum agitation technique to enhance thrombus dissolution and drainage and to apply the technique to a porcine-retained hemothorax. Methods. Three agitation techniques were tested: flush irrigation, ultrasound, and vibration. We used the techniques in a benchtop model with tissue plasminogen activator (tPA) and pig hemothorax with tPA. We used the most promising technique vibration in a pig hemothorax without tPA. Statistics. We used 2-sample t tests for each comparison and Cohen d tests to calculate effect size (ES). Results. In the benchtop model, mean drainages in the agitation group and control group and the ES were flush irrigation, 42%, 28%, and 2.91 (P = .10); ultrasound, 35%, 27%, and .76 (P = .30); and vibration, 28%, 19%, and 1.14 (P = .04). In the pig hemothorax with tPA, mean drainages and the ES of each agitation technique compared with control (58%) were flush irrigation, 80% and 1.14 (P = .37); ultrasound, 80% and 2.11 (P = .17); and vibration, 95% and 3.98 (P = .06). In the pig hemothorax model without tPA, mean drainages of the vibration technique and control group were 50% and 43% (ES = .29; P = .65). Discussion. In vitro studies suggested flush irrigation had the greatest effect, whereas only vibration was significantly different vs the respective controls. In vivo with tPA, vibration showed promising but not statistically significant results. Results of in vivo experiments without tPA were negative. Conclusion. Agitation techniques, in combination with tPA, may enhance drainage of hemothorax.
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Affiliation(s)
- Ian A Makey
- Department of Cardiothoracic Surgery, Mayo Clinic, FL, USA
| | - Nitin A Das
- Department of Cardiothoracic Surgery, University of Texas Health San Antonio, TX, USA
| | - Samuel Jacob
- Department of Cardiothoracic Surgery, Mayo Clinic, FL, USA
| | | | | | - Scott B Johnson
- Department of Cardiothoracic Surgery, University of Texas Health San Antonio, TX, USA
| | - Mathew Thomas
- Department of Cardiothoracic Surgery, Mayo Clinic, FL, USA
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Janjic J, Larsson MK, Bjällmark A. In-vitro sonothrombolysis using thick-shelled polymer microbubbles - a comparison with thin-shelled microbubbles. Cardiovasc Ultrasound 2020; 18:12. [PMID: 32366318 PMCID: PMC7197129 DOI: 10.1186/s12947-020-00194-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/16/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Vascular thrombosis can be treated pharmacologically, however, serious shortcomings such as bleeding may occur. Several studies suggest that sonothrombolysis can induce lysis of the clots using ultrasound. Moreover, intravenously injected thin-shelled microbubbles (MBs) combined with ultrasound can further improve clot lysis. Thick-shelled MBs have been used for drug delivery, targeting and multimodal imaging. However, their capability to enhance sonothrombolysis is unknown. In this study, using an in-vitro set-up, the enhancement of clot lysis using ultrasound and thick-shelled MBs was investigated. Thin-shelled MBs was used for comparison. METHOD The main components in the in-vitro set-up was a vessel mimicking phantom, a pressure mearing system and programmable ultrasound machine. Blood clots were injected and entrapped on a pore mesh in the vessel phantom. Four different protocols for ultrasound transmission and MB exposure (7 blood clots/protocol) were considered together with a control test were no MBs and ultrasound were used. For each protocol, ultrasound exposure of 20 min was used. The upstream pressure of the partially occluded mesh was continuously measured to assess clot burden. At the end of each protocol blood clots were removed from the phantom and the clot mass loss was computed. RESULTS For the thick-shelled MBs no difference in clot mass loss compared with the control tests was found. A 10% increase in the clot mass loss compared with the control tests was found when using thin-shelled MBs and low pressure/long pulses ultrasound exposure. Similarly, in terms of upstream pressure over exposure time, no differences were found when using the thick-shelled MBs, whereas thin-shelled MBs showed a 15% decrease achieved within the first 4 min of ultrasound exposure. CONCLUSION No increase in clot lysis was achieved using thick-shelled MBs as demonstrated by no significant change in clot mass or upstream pressure. Although thick-shelled MBs are promising for targeting and drug delivery, they do not enhance clot lysis when considering the ultrasound sequences used in this study. On the other hand, ultrasound in combination with thin-shelled MBs can facilitate thrombolysis when applying long ultrasound pulses with low pressure.
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Affiliation(s)
- Jovana Janjic
- Biosense Webster, Johnson & Johnson Medical, Via del Mare 56, 00071 Pomezia, Rome, Italy
| | - Malin K Larsson
- Karolinska University Hospital, Eugeniavägen 3, SE-171 76, Stockholm, Sweden
| | - Anna Bjällmark
- Department of Natural Science and Biomedicine, School of Health and Welfare, Jönköping University, Gjuterigatan 5, SE-553 18, Jönköping, Sweden.
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Black JJ, Yu FTH, Schnatz RG, Chen X, Villanueva FS, Pacella JJ. Effect of Thrombus Composition and Viscosity on Sonoreperfusion Efficacy in a Model of Micro-Vascular Obstruction. ULTRASOUND IN MEDICINE & BIOLOGY 2016; 42:2220-31. [PMID: 27207018 PMCID: PMC4983511 DOI: 10.1016/j.ultrasmedbio.2016.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 03/28/2016] [Accepted: 04/06/2016] [Indexed: 05/11/2023]
Abstract
Distal embolization of micro-thrombi during stenting for myocardial infarction causes micro-vascular obstruction (MVO). We have previously shown that sonoreperfusion (SRP), a microbubble (MB)-mediated ultrasound (US) therapy, resolves MVO from venous micro-thrombi in vitro in saline. However, blood is more viscous than saline, and arterial thrombi that embolize during stenting are mechanically distinct from venous clot. Therefore, we tested the hypothesis that MVO created with arterial micro-thrombi are more resistant to SRP therapy compared with venous micro-thrombi, and higher viscosity further increases the US requirement for effective SRP in an in vitro model of MVO. Lipid MBs suspended in plasma with adjusted viscosity (1.1 cP or 4.0 cP) were passed through tubing bearing a mesh with 40-μm pores to simulate a micro-vascular cross-section; upstream pressure reflected thrombus burden. To simulate MVO, the mesh was occluded with either arterial or venous micro-thrombi to increase upstream pressure to 40 mmHg ± 5 mmHg. Therapeutic long-tone-burst US was delivered to the occluded area for 20 min. MB activity was recorded with a passive cavitation detector. MVO caused by arterial micro-thrombi at either blood or plasma viscosity resulted in less effective SRP therapy compared to venous thrombi. Higher viscosity further reduced the effectiveness of SRP therapy. The passive cavitation detector showed a decrease in inertial cavitation when viscosity was increased, while stable cavitation was affected in a more complex manner. Overall, these data suggest that arterial thrombi may require higher acoustic pressure US than venous thrombi to achieve similar SRP efficacy; increased viscosity decreases SRP efficacy; and both inertial and stable cavitation are implicated in observed SRP efficacy.
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Affiliation(s)
- John J Black
- Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Francois T H Yu
- Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Rick G Schnatz
- Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Xucai Chen
- Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Flordeliza S Villanueva
- Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - John J Pacella
- Center for Ultrasound Molecular Imaging and Therapeutics, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
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Ammi AY, Lindner JR, Zhao Y, Porter T, Siegel R, Kaul S. Efficacy and spatial distribution of ultrasound-mediated clot lysis in the absence of thrombolytics. Thromb Haemost 2015; 113:1357-69. [PMID: 25809056 DOI: 10.1160/th14-03-0286] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 01/17/2015] [Indexed: 11/05/2022]
Abstract
Ultrasound and microbubble (MB) contrast agents accelerate clot lysis, yet clinical trials have been performed without defining optimal acoustic conditions. Our aim was to assess the effect of acoustic pressure and frequency on the extent and spatial location of clot lysis. Clots from porcine blood were created with a 2-mm central lumen for infusion of lipid-shelled perfluorocarbon MBs (1×10(7) ml(-1)) or saline. Therapeutic ultrasound at 0.04, 0.25, 1.05, or 2.00 MHz was delivered at a wide range of peak rarefactional acoustic pressure amplitudes (PRAPAs). Ultrasound was administered over 20 minutes grouped on-off cycles to allow replenishment of MBs. The region of lysis was quantified using contrast-enhanced ultrasound imaging. In the absence of MBs, sonothrombolysis did not occur at any frequency. Sonothrombolysis was also absent in the presence of MBs despite their destruction at 0.04 and 2.00 MHz. It occurred at 0.25 and 1.05 MHz in the presence of MBs for PRAPAs > 1.2 MPa and increased with PRAPA. At 0.25 MHz the clot lysis was located in the far wall. At 1.05 MHz, however, there was a transition from far to near wall as PRAPA was increased. The area of clot lysis measured by ultrasound imaging correlated with that by micro-CT and quantification of debris in the effluent. In conclusion, sonothrombolysis with MBs was most efficient at 0.25 MHz. The spatial location of sonothrombolysis varies with pressure and frequency indicating that the geometric relation between therapeutic probe and vascular thrombosis is an important variable for successful lysis clinically.
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Affiliation(s)
- Azzdine Y Ammi
- Azzdine Y. Ammi, PhD, Knight Cardiovascular Institute, UHN-62, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA, Tel.: +1 503 494 8750, Fax: +1 503 494 8550, E-mail:
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Goertz DE. An overview of the influence of therapeutic ultrasound exposures on the vasculature: high intensity ultrasound and microbubble-mediated bioeffects. Int J Hyperthermia 2015; 31:134-44. [PMID: 25716770 DOI: 10.3109/02656736.2015.1009179] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It is well established that the interaction of ultrasound with soft tissues can induce a wide range of bioeffects. One of the most important and complex of these interactions in the context of therapeutic ultrasound is with the vasculature. Potential vascular effects range from enhancing microvascular permeability to inducing vascular damage and vessel occlusion. While aspects of these effects are broadly understood, the development of improved approaches to exploit these effects and gain a more detailed mechanistic understanding is ongoing and largely anchored in preclinical research. Here a general overview of this established yet rapidly evolving topic is provided, with a particular emphasis on effects arising from high-intensity focused ultrasound and microbubble-mediated exposures.
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Affiliation(s)
- David E Goertz
- Department of Physical Sciences, Sunnybrook Health Sciences Center , Toronto, Ontario , Canada
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Acconcia C, Leung BYC, Manjunath A, Goertz DE. Interactions between individual ultrasound-stimulated microbubbles and fibrin clots. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:2134-2150. [PMID: 24882525 DOI: 10.1016/j.ultrasmedbio.2014.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 02/23/2014] [Accepted: 03/06/2014] [Indexed: 06/03/2023]
Abstract
The use of ultrasound-stimulated microbubbles (USMBs) to promote thrombolysis is well established, but there remains considerable uncertainty about the mechanisms of this process. Here we examine the microscale interactions between individual USMBs and fibrin clots as a function of bubble size, exposure conditions and clot type. Microbubbles (n = 185) were placed adjacent to clot boundaries ("coarse" or "fine") using optical tweezers and exposed to 1-MHz ultrasound as a function of pressure (0.1-0.39 MPa). High-speed (10 kfps) imaging was employed, and clots were subsequently assessed with 2-photon microscopy. For fine clots, 46% of bubbles "embedded" within 10 μm of the clot boundary at pressures of 0.1 and 0.2 MPa, whereas at 0.39 MPa, 53% of bubbles penetrated and transited into the clots with an incidence inversely related to their diameter. A substantial fraction of penetrating bubbles induced fibrin network damage and promoted the uptake of nanobeads. In coarse clots, penetration occurred more readily and at lower pressures than in fine clots. The results therefore provide direct evidence of therapeutically relevant effects of USMBs and indicate their dependence on size, exposure conditions and clot properties.
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Affiliation(s)
- Christopher Acconcia
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Research Institute, Toronto, Ontario, Canada.
| | - Ben Y C Leung
- Sunnybrook Research Institute, Toronto, Ontario, Canada
| | | | - David E Goertz
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Research Institute, Toronto, Ontario, Canada
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Shih CP, Chen HC, Chen HK, Chiang MC, Sytwu HK, Lin YC, Li SL, Shih YF, Liao AH, Wang CH. Ultrasound-aided microbubbles facilitate the delivery of drugs to the inner ear via the round window membrane. J Control Release 2013; 167:167-74. [PMID: 23391441 DOI: 10.1016/j.jconrel.2013.01.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 12/23/2012] [Accepted: 01/20/2013] [Indexed: 10/27/2022]
Abstract
The round window membrane (RWM) acts as a barrier between the middle ear and cochlea and can serve as a crucial route for therapeutic medications entering the inner ear via middle ear applications. In this study, we targeted the practical application of microbubbles (MBs) ultrasound on increasing the RWM permeability for facilitating drug or medication delivery to the inner ear. Using biotin-fluorescein isothiocyanate conjugates (biotin-FITC) as delivery agents and guinea pig animal models, we showed that MB ultrasound exposure can improve the inner ear system use of biotin-FITC delivery via the RWM by approximately 3.5 to 38 times that of solely soaking biotin-FITC around the RWM for spontaneous diffusion. We also showed that there was significant enhancement of hair cell uptake of gentamicin in animals whose tympanic bullas were soaked with MB-mixed gentamicin-Texas Red or gentamicin and exposed to ultrasound. Furthermore, increased permeability of the RWM from acoustic cavitation of MBs could also be visualized immediately following ultrasound exposure by using Alexa Fluor 488-conjugated phalloidin as a tracer. Most importantly, such applications had no resulting damage to the integrity of the RWM or deterioration of the hearing thresholds assessed by auditory brainstem responses. We herein provide a basis for MB ultrasound-mediated techniques with therapeutic medication delivery to the inner ear for future application in humans.
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Affiliation(s)
- Cheng-Ping Shih
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, ROC
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Chuang YH, Cheng PW, Li PC. Combining radiation force with cavitation for enhanced sonothrombolysis. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2013; 60:97-104. [PMID: 23287916 DOI: 10.1109/tuffc.2013.2541] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The use of acoustic radiation force has been suggested for enhancing the delivery of therapeutic substances, whereas sonothrombolysis has been developed for years as treatment by itself, or in combination with thrombolytic agents or ultrasound contrast agents. We have examined the efficacy of using acoustic radiation force to enhance the targeting of microbubbles in cavitation-induced sonothrombolysis in a flow phantom system. A clot was targeted by microbubbles using avidin-biotin binding, and the process was observed using a confocal microscope. We found that the experimental group in which radiation force was combined with cavitation showed an additional 3% to 9% weight reduction of the thrombus relative to the cavitation group. We also found that the fluorescence intensity of the clot increased with the microbubble concentration at each acoustic setting. Microbubbles traveled 10 to 20 μm further than the control group after being exposed to radiation force, cavitation, or both. These observations confirm that radiation force helps microbubbles to distribute into a clot (as does cavitation). Therefore, combining radiation force with cavitation would provide additional thrombolysis effects (based on clot weight measurements) relative to cavitation alone. A local delivery method based on acoustic radiation force has the potential to improve the safety and efficacy of sonothrombolysis.
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Affiliation(s)
- Yueh-Hsun Chuang
- Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
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12
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Removing vascular obstructions: a challenge, yet an opportunity for interventional microdevices. Biomed Microdevices 2012; 14:511-32. [PMID: 22331446 DOI: 10.1007/s10544-011-9627-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cardiovascular diseases are the leading cause of death worldwide; they are mainly due to vascular obstructions which, in turn, are mainly caused by thrombi and atherosclerotic plaques. Although a variety of removal strategies has been developed for the considered obstructions, none of them is free from limitations and conclusive. The present paper analyzes the physical mechanisms underlying state-of-art removal strategies and classifies them into chemical, mechanical, laser and hybrid (namely chemo-mechanical and mechano-chemical) approaches, while also reviewing corresponding commercial/research tools/devices and procedures. Furthermore, challenges and opportunities for interventional micro/nanodevices are highlighted. In this spirit, the present review should support engineers, researchers active in the micro/nanotechnology field, as well as medical doctors in the development of innovative biomedical solutions for treating vascular obstructions. Data were collected by using the ISI Web of Knowledge portal, buyer's guides and FDA databases; devices not reported on scientific publications, as well as commercial devices no more for sale were discarded. Nearly 70% of the references were published since 2006, 55% since 2008; these percentages respectively raise to 85% and 65% as regards the section specifically reviewing state-of-art removal tools/devices and procedures.
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Abstract
OBJECTIVES To characterize the ability of high-intensity focused ultrasound to achieve thrombolysis in vitro and investigate the feasibility of this approach as a means of restoring blood flow in thrombus-occluded arteries in vivo. MATERIALS AND METHODS All experiments were approved by the Institutional Animal Care Committee. Thrombolysis was performed with a 1.51-MHz focused ultrasound transducer with pulse lengths of 0.1 to 10 milliseconds and acoustic powers up to 300 W. In vitro experiments were performed with blood clots formed from rabbit arterial blood and situated in 2-mm diameter tubing. Both single location and flow bypass recanalization experiments were conducted. In vitro clot erosion was assessed with 30-MHz ultrasound, with debris size measured with filters and a Coulter counter. In vivo clots were initiated in the femoral arteries of rabbits (n = 26). Cavitation signals from bubbles formed during exposure were monitored. In vivo flow restoration was assessed with 23-MHz Doppler ultrasound. RESULTS At a single location, in vitro clot erosion volumes increased with exposure power and pulse length, with debris size reducing with increasing pulse length. Flow bypass experiments achieved 99.2% clot erosion with 1.1% of debris above 0.5 mm in size. In vivo, 10 milliseconds pulses were associated with bleeding, but at 1 millisecond, it was feasible to achieve partial flow restoration in 6 of the 10 clots with only 1 of the 10 showing evidence of bleeding. In all cases, thrombolysis occurred only in the presence of cavitation. CONCLUSION High-intensity focused ultrasound thrombolysis is feasible as a means of restoring partial blood flow in thrombus-occluded arteries in the absence of thrombolytic agents. The potential for bleeding with this approach requires further investigation.
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Slikkerveer J, Kleijn SA, Appelman Y, Porter TR, Veen G, van Rossum AC, Kamp O. Ultrasound enhanced prehospital thrombolysis using microbubbles infusion in patients with acute ST elevation myocardial infarction: pilot of the Sonolysis study. ULTRASOUND IN MEDICINE & BIOLOGY 2012; 38:247-52. [PMID: 22178160 DOI: 10.1016/j.ultrasmedbio.2011.11.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Revised: 10/27/2011] [Accepted: 11/05/2011] [Indexed: 05/07/2023]
Abstract
In animal studies, transthoracic ultrasound and microbubbles have shown to dissolve thrombi in ST elevation myocardial infarction (STEMI). To examine this effect in patients, we have initiated the Sonolysis trial. In this pilot study of 10 patients with a first acute STEMI, we investigated the safety and feasibility of this trial. After pretreatment in the ambulance, five patients were randomized to receive microbubbles with three-dimensional (3-D) guided high mechanical index impulses (1.18) for 15 min, whereas the control group received placebo without ultrasound. Subsequently, primary percutaneous coronary intervention (PPCI) was performed, if indicated. All patients successfully underwent study treatment and PPCI. No significant difference between treatment and control group in safety (minor adverse events 2/5 vs. 2/5, p = NS) and outcome (TIMI III flow 3/5 vs. 1/5 respectively, p = 0.23) was recorded. These results demonstrate that the study protocol is feasible in the acute cardiac care setting and safe during treatment and follow-up.
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Affiliation(s)
- Jeroen Slikkerveer
- Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands.
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15
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Wright CC, Hynynen K, Goertz DE. Pulsed focused ultrasound-induced displacements in confined in vitro blood clots. IEEE Trans Biomed Eng 2011; 59:842-51. [PMID: 22194235 DOI: 10.1109/tbme.2011.2180904] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Ultrasound has been shown to potentiate the effects of tissue plasminogen activator to improve clot lysis in a range of in vitro and in vivo studies as well as in clinical trials. One possible mechanism of action is acoustic radiation force-induced clot displacements. In this study, we investigate the temporal and spatial dynamics of clot displacements and strain initiated by focused ultrasound pulses. Displacements were produced by a 1.51 MHz f-number 1 transducer over a range of acoustic powers (1-85 W) in clots constrained within an agar vessel phantom channel. Displacements were tracked during and after a 5.45 ms therapy pulse using a 20 MHz high-frequency ultrasound imaging probe. Peak thrombus displacements were found to be linear as a function of acoustic power up to 60 W before leveling off near 128 μm for the highest transmit powers. The time to peak displacement and recovery time of blood clots was largely independent of acoustic powers with measured values near 2 ms. A linear relationship between peak axial strain and transmit power was observed, reaching a peak value of 11% at 35 W. The peak strain occurred ~0.75 mm from the focal zone for all powers investigated in both lateral and axial directions. These results indicate that substantial displacements can be induced by focused ultrasound in confined blood clots, and that the spatial and temporal displacement patterns are complex and highly dependent on exposure conditions, which has implications for future work investigating their link to clot lysis and for developing approaches to exploit these effects.
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Affiliation(s)
- Cameron C Wright
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
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16
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Zhou XB, Qin H, Li J, Wang B, Wang CB, Liu YM, Jia XD, Shi N. Platelet-targeted microbubbles inhibit re-occlusion after thrombolysis with transcutaneous ultrasound and microbubbles. ULTRASONICS 2011; 51:270-274. [PMID: 20888024 DOI: 10.1016/j.ultras.2010.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 07/05/2010] [Accepted: 09/01/2010] [Indexed: 05/29/2023]
Abstract
Microbubbles (MBs) can augment the acoustic cavitation' (US), thereby facilitating the thrombolysis of external ultrasound. But we observed re-thrombosis after successful thrombolysis by MBs and transcutaneous ultrasound in an endothelium injury model. This study was designed to explore whether platelet-targeted MBs can prevent the reformation of thrombi. Arterial injury was induced in canine femoral arteries with balloon, and the arteries were completely thrombotically occluded. The arteries were treated with intra-arterial MBs or platelet-targeted MBs (TMB) and transcutaneous low frequency ultrasound (LFUS) to achieve complete thrombolysis. The arterial flow was monitored with angiogram for 4h following treatment. Results showed that both MBs and TMBs produced successful dissolution of clots in the presence of ultrasound. The re-occlusion began to occur 1h after thrombolysis in MB/LFUS treatment, and 7 of 8 arteries were re-occluded within 3h. Most of the arteries (7 of 8) in the TMB/LFUS group remained patent for 4h following treatment. The flow tended to decrease after thrombolysis in MB/LFUS treatment. These results indicated that platelet-targeted microbubbles were beneficial in preventing re-thrombosis in vivo and microbubbles served as good carrier of thrombolytic and anticoagulation drugs.
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Affiliation(s)
- X B Zhou
- School of Medicine, Xi'an Jiaotong University, Xi'an, People's Republic of China
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17
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Maxwell AD, Owens G, Gurm HS, Ives K, Myers DD, Xu Z. Noninvasive treatment of deep venous thrombosis using pulsed ultrasound cavitation therapy (histotripsy) in a porcine model. J Vasc Interv Radiol 2010; 22:369-77. [PMID: 21194969 DOI: 10.1016/j.jvir.2010.10.007] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 06/14/2010] [Accepted: 10/12/2010] [Indexed: 11/25/2022] Open
Abstract
PURPOSE This study evaluated histotripsy as a noninvasive, image-guided method of thrombolysis in a porcine model of deep vein thrombosis. Histotripsy therapy uses short, high-intensity, focused ultrasound pulses to cause mechanical breakdown of targeted soft tissue by acoustic cavitation, which is guided by real-time ultrasound imaging. This is an in vivo feasibility study of histotripsy thrombolysis. METHODS AND MATERIALS Acute thrombi were formed in the femoral vein of juvenile pigs weighing 30-40 kg by balloon occlusion with two catheters and thrombin infusion. A 10-cm-diameter 1-MHz focused transducer was used for therapy. An 8-MHz ultrasound imager was used to align the clot with the therapy focus. Therapy consisted of five cycle pulses delivered at a rate of 1 kHz and peak negative pressure between 14 and 19 MPa. The focus was scanned along the long axis of the vessel to treat the entire visible clot during ultrasound exposure. The targeted region identified by a hyperechoic cavitation bubble cloud was visualized via ultrasound during treatment. RESULTS Thrombus breakdown was apparent as a decrease in echogenicity within the vessel in 10 of 12 cases and in 7 cases improved flow through the vein as measured by color Doppler. Vessel histology found denudation of vascular endothelium and small pockets of hemorrhage in the vessel adventitia and underlying muscle and fatty tissue, but perforation of the vessel wall was never observed. CONCLUSIONS The results indicate histotripsy has potential for development as a noninvasive treatment for deep vein thrombosis.
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Affiliation(s)
- Adam D Maxwell
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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18
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Jones G, Hunter F, Hancock HA, Kapoor A, Stone MJ, Wood BJ, Xie J, Dreher MR, Frenkel V. In vitro investigations into enhancement of tPA bioavailability in whole blood clots using pulsed-high intensity focused ultrasound exposures. IEEE Trans Biomed Eng 2010; 57:33-6. [PMID: 20064753 DOI: 10.1109/tbme.2009.2028316] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Investigations were carried out on the manner by which pulsed-high intensity focused ultrasound (HIFU) enhances the effectiveness of tissue plasminogen activator (tPA) in whole blood clots, in vitro. Scanning electronic microscope (SEM) of the surface of the clots showed that the exposures increased exposed fibrin, as well as the number of openings to more interior regions. These findings were supported by fluorescent antibody labeling of tPA in frozen sections of clots treated post-HIFU. Here, improved accumulation at the surface and penetration of the tPA into the clots were observed in those treated with HIFU. Fluorescence recovery after photobleaching was also performed, indicating that the diffusion coefficient increased 6.3-fold for fluorescently labeled dextrans, comparable in size to tPA, in the HIFU-treated clots. Improved understanding of the manner by which pulsed--HIFU exposures can improve the effectiveness of thrombolytics will help optimize the exposures for this application and potentially facilitate translation to the clinic.
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Affiliation(s)
- Guy Jones
- Department of Radiology and ImagingSciences, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
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19
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Xuedong Shen, Nair C, Holmberg M, Mooss A, Arouni A, Esterbrooks D. Therapeutic Ultrasound-Enhanced Thrombolysis in Patients With Acute Myocardial Infarction. Angiology 2009; 61:253-8. [DOI: 10.1177/0003319709343287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thrombolytic therapy is widely used to treat the patients with ST elevation acute myocardial infarction (STE-MI). Due to logistic and economic reasons, only 10% of patients with acute myocardial infarction can be treated with the percutaneous coronary intervention (PCI). Optimal flow (TIMI (Thrombolysis In Myocardial Infarction) 3 flow) is achieved in only about 60% of cases by enzymatic thrombolysis. Therapeutic ultrasound (US) exerts an effect on thrombolysis by micromechanical processes or indirectly by supporting enzymatic thrombolysis. This review examines relevant experimental and clinical published data. Technical issues in therapeutic US-enhanced thrombolysis in patients with acute myocardial infarction and advancements of the techniques during recent 10 years are discussed.
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Affiliation(s)
- Xuedong Shen
- Department of Cardiology, The Cardiac Center of Creighton University, Omaha, Nebraska,
| | - Chandra Nair
- Department of Cardiology, The Cardiac Center of Creighton University, Omaha, Nebraska
| | - Mark Holmberg
- Department of Cardiology, The Cardiac Center of Creighton University, Omaha, Nebraska
| | - Aryan Mooss
- Department of Cardiology, The Cardiac Center of Creighton University, Omaha, Nebraska
| | - Amy Arouni
- Department of Cardiology, The Cardiac Center of Creighton University, Omaha, Nebraska
| | - Dennis Esterbrooks
- Department of Cardiology, The Cardiac Center of Creighton University, Omaha, Nebraska
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20
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Yamashita T, Ohtsuka H, Arimura N, Sonoda S, Kato C, Ushimaru K, Hara N, Tachibana K, Sakamoto T. Sonothrombolysis for intraocular fibrin formation in an animal model. ULTRASOUND IN MEDICINE & BIOLOGY 2009; 35:1845-1853. [PMID: 19699025 DOI: 10.1016/j.ultrasmedbio.2009.05.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 05/22/2009] [Accepted: 05/28/2009] [Indexed: 05/28/2023]
Abstract
Vascular diseases such as diabetic retinopathy or retinal arterial occlusion are always associated with retinal and/or choroidal vasculopathy and intravascular thrombosis is commonly found. The ultrasound (US) therapy is a recently developed technique to accelerate fibrinolysis and it is being applied to some clinical fields. The present study was to observe the effects of extraocular US exposure on intraocular fibrin, which is a deteriorating factor in various ocular diseases. Tubes containing human blood (2 mL) in the following groups were irradiated with US; US alone, US with tissue plasminogen activator (tPA), tPA alone, and saline (control). Fibrinolysis was quantified by measuring D-dimer after 2h. In rat eyes, intracameral fibrin (fibrin formation in the anterior chamber of the eye) was induced by YAG-laser-induced iris bleeding. Then, eyes in the following groups were irradiated with US; US alone, subconjunctival tPA alone, US and subconjunctival tPA, control. Intracameral fibrin was scored on day 3 (3+ maximum to 0). The temperatures of rat eyes were measured by infrared thermography. Histologic evaluation was also performed. D-dimer was increased by US with statistical significance (p <0.05) or tPA (p <0.01). D-dimer in US with tPA group was significantly higher than either US alone or tPA alone group (p <0.01). In rat eyes, the average intracameral fibrin score on day 3 was 1.4 in control group and 1.2 in subconjunctival tPA alone group; however, it decreased significantly in the US alone group (0.75; p <0.05, vs. control), US and subconjunctival tPA group (0.71; p <0.01, vs. control). The temperature was less than 34 degrees C after US exposure. No histologic damage was observed. US irradiation from outside accelerated intracameral fibrinolysis without causing apparent tissue damage. This noninvasive method might have therapeutic value for intraocular fibrin.
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Affiliation(s)
- Toshifumi Yamashita
- Department of Ophthalmology, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima 890-8520, Japan
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Abstract
OBJECTIVES Use of ultrasound in therapeutics and drug delivery has gained importance in recent years, evident by the increase in patents filed and new commercial devices launched. The present review discusses new advancements in sonophoretic drug delivery in the last two decades, and highlights important challenges still to be met to make this technology of more use in the alleviation of diseases. KEY FINDINGS Phonophoretic research often suffers from poor calibration in terms of the amount of ultrasound energy emitted, and therefore current research must focus on safety of exposure to ultrasound and miniaturization of devices in order to make this technology a commercial reality. More research is needed to identify the role of various parameters influencing sonophoresis so that the process can be optimized. Establishment of long-term safety issues, broadening the range of drugs that can be delivered through this system, and reduction in the cost of delivery are issues still to be addressed. SUMMARY Sonophoresis (phonophoresis) has been shown to increase skin permeability to various low and high molecular weight drugs, including insulin and heparin. However, its therapeutic value is still being evaluated. Some obstacles in transdermal sonophoresis can be overcome by combination with other physical and chemical enhancement techniques. This review describes recent advancements in equipment and devices for phonophoresis, new formulations tried in sonophoresis, synergistic effects with techniques such as chemical enhancers, iontophoresis and electroporation, as well as the growing use of ultrasound in areas such as cancer therapy, cardiovascular disorders, temporary modification of the blood-brain barrier for delivery of imaging and therapeutic agents, hormone replacement therapy, sports medicine, gene therapy and nanotechnology. This review also lists patents pertaining to the formulations and techniques used in sonophoretic drug delivery.
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Affiliation(s)
- Rekha Rao
- M. M. College of Pharmacy, M. M. University, Mullana, 133001, India
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22
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Porter TR. The utilization of ultrasound and microbubbles for therapy in acute coronary syndromes. Cardiovasc Res 2009; 83:636-42. [PMID: 19541670 DOI: 10.1093/cvr/cvp206] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ultrasound has become a useful high resolution imaging modality for examining the cardiac microcirculation. With the use of microbubbles as an ultrasound contrast agent, ultrasound can be utilized to image the microcirculation and detect capillary flow abnormalities in acute ischaemia. A wide range of ultrasound frequencies (including those used for diagnostic transthoracic imaging) have also been utilized therapeutically to augment the effectiveness of fibrinolytic therapy in ST-segment elevation myocardial infarction (STEMI). Ultrasound and microbubbles are now being explored as methods of improving both microcirculatory and epicardial flow in acute STEMI. This article will review the mechanisms by which ultrasound and microbubbles assist in thrombus detection and dissolution. In addition, the pre-clinical studies utilizing transthoracic ultrasound as a therapeutic entity in acute STEMI will be reviewed. Clinical studies, completed and ongoing, will also be presented.
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Affiliation(s)
- Thomas R Porter
- University of Nebraska Medical Center, 982265 Nebraska Medical Center, Omaha, NE 68198-2265, USA.
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23
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O'Neill BE, Li KCP. Augmentation of targeted delivery with pulsed high intensity focused ultrasound. Int J Hyperthermia 2009; 24:506-20. [PMID: 18608574 DOI: 10.1080/02656730802093661] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
This paper reviews the enhanced delivery of genes, drugs and therapeutics using ultrasound. It begins with a general overview of the field and the various techniques associated with it, including sonophoresis, hyperthermia (with ultrasound), sonoporation, and microbubble assisted transvascular and targeted delivery. Particular attention is then paid to pulsed high intensity focused ultrasound drug delivery without the use of ultrasound contrast agents. Feasibility and mechanistic studies of this technique are described in some detail. Conclusions are then drawn regarding possible mechanisms of this treatment, and to contrast with the better known treatments relying on injection of ultrasound contrast agents.
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Affiliation(s)
- Brian E O'Neill
- Department of Radiology, The Methodist Hospital, Houston, TX 77030, USA
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24
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Slikkerveer J, Dijkmans PA, Sieswerda GT, Doevendans PAFM, van Dijk APJ, Verheugt FWA, Porter TR, Kamp O. Ultrasound enhanced prehospital thrombolysis using microbubbles infusion in patients with acute ST elevation myocardial infarction: rationale and design of the Sonolysis study. Trials 2008; 9:72. [PMID: 19068143 PMCID: PMC2614934 DOI: 10.1186/1745-6215-9-72] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Accepted: 12/10/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Experimental studies have shown that ultrasound contrast agents enhance the effectiveness of thrombolytic agents in the presence of ultrasound in vitro and in vivo. Recently, we have launched a clinical pilot study, called "Sonolysis", to study this effect in patients with ST-elevation myocardial infarction based on proximal lesions of the infarct-related artery. METHODS/DESIGN In our multicenter, randomized, placebo controlled clinical trial we will include patients between 18 and 80 years of age with their first ST-elevation myocardial infarction based on a proximal lesion of the infarct-related artery. After receiving a single bolus alteplase 50 mg IV (Actilyse(R) Boehringer Ingelheim GmbH), a loading dose of aspirin 500 mg, and heparin 5000 IU in the ambulance according to the prehospital thrombolysis protocol, patients, following oral informed consent, are randomized to undergo 15 minutes of pulsatile ultrasound with intravenous administration of ultrasound contrast agent or placebo without ultrasound. Afterwards coronary angiography and, if indicated, percutaneous coronary intervention will take place. A total of 60 patients will be enrolled in approximately 1 year.The primary endpoints are based on the coronary angiogram and consist of TIMI flow, corrected TIMI frame count, and myocardial blush grade. Follow-up includes 12-lead ECG, 2D-echocardiography, cardiac MRI, and enzyme markers to obtain our secondary endpoints, including the infarct size, wall motion abnormalities, and the global left ventricular function. DISCUSSION The Sonolysis study is the first multicenter, randomized, placebo controlled clinical trial investigating the therapeutic application of ultrasound and microbubbles in acute ST-elevation myocardial infarction patients. A positive finding may stimulate further research and technical innovations to implement the treatment in the ambulance and maybe obtain even more patency at an earlier stage. TRIAL REGISTRATION Trialregister NTR161.
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Affiliation(s)
- Jeroen Slikkerveer
- Department of Cardiology and Institute of Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
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25
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Ultrasonic gene and drug delivery to the cardiovascular system. Adv Drug Deliv Rev 2008; 60:1177-92. [PMID: 18474407 DOI: 10.1016/j.addr.2008.03.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Accepted: 03/04/2008] [Indexed: 11/22/2022]
Abstract
Ultrasound targeted microbubble destruction has evolved as a promising tool for organ specific gene and drug delivery. This technique has initially been developed as a method in myocardial contrast echocardiography, destroying intramyocardial microbubbles to characterize refill kinetics. When loading similar microbubbles with a bioactive substance, ultrasonic destruction of microbubbles may release the transported substance in the targeted organ. Furthermore, high amplitude oscillations of microbubbles lead to increased capillary and cell membrane permeability, thus facilitating tissue and cell penetration of the released substance. While this technique has been successfully used in many organs, its application in the cardiovascular system has dominated so far. Drug delivery using microbubbles has played a minor role in the cardiovascular system. In contrast, gene transfer has been successfully achieved in many studies. Both viral and non-viral vectors were used for loading on microbubbles. This review article will give an overview on studies that have applied ultrasound targeted microbubble destruction to deliver substances in the heart and blood vessels. It will show potential therapeutic targets, especially for gene therapy, describe feasible substances that can be loaded on microbubbles, and critically discuss prospects and limitations of this technique.
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26
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Frenkel V. Ultrasound mediated delivery of drugs and genes to solid tumors. Adv Drug Deliv Rev 2008; 60:1193-208. [PMID: 18474406 DOI: 10.1016/j.addr.2008.03.007] [Citation(s) in RCA: 332] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Accepted: 03/04/2008] [Indexed: 12/21/2022]
Abstract
It has long been shown that therapeutic ultrasound can be used effectively to ablate solid tumors, and a variety of cancers are presently being treated in the clinic using these types of ultrasound exposures. There is, however, an ever-increasing body of preclinical literature that demonstrates how ultrasound energy can also be used non-destructively for increasing the efficacy of drugs and genes for improving cancer treatment. In this review, a summary of the most important ultrasound mechanisms will be given with a detailed description of how each one can be employed for a variety of applications. This includes the manner by which acoustic energy deposition can be used to create changes in tissue permeability for enhancing the delivery of conventional agents, as well as for deploying and activating drugs and genes via specially tailored vehicles and formulations.
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27
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Nahirnyak V, Mast TD, Holland CK. Ultrasound-induced thermal elevation in clotted blood and cranial bone. ULTRASOUND IN MEDICINE & BIOLOGY 2007; 33:1285-95. [PMID: 17490808 PMCID: PMC2147060 DOI: 10.1016/j.ultrasmedbio.2007.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 01/06/2007] [Accepted: 02/09/2007] [Indexed: 05/15/2023]
Abstract
Ultrasound thermal effects have been hypothesized to contribute to ultrasound-assisted thrombolysis. To explore the thermal mechanism of ultrasound-enhanced thrombolysis with recombinant tissue plasminogen activator (rt-PA) for the treatment of ischemic stroke, a detailed investigation is needed of the heating produced in skull, brain and blood clots. A theoretical model is developed to provide an estimate for the worst-case scenario of the temperature increase in blood clots and on the surface of cranial bone exposed to 0.12- to 3.5-MHz ultrasound. Thermal elevation was also assessed experimentally in human temporal bone, human clots and porcine clots exposed to 0.12 to 3.5-MHz pulsed ultrasound in vitro with a peak-to-peak pressure of 0.25 MPa and 80% duty cycle. Blood clots exposed to 0.12-MHz pulsed ultrasound exhibited a small temperature increase (0.25 degrees C) and bone exposed to 1.0-MHz pulsed ultrasound exhibited the highest temperature increase (1.0 degrees C). These experimental results were compared with the predicted temperature elevations.
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Affiliation(s)
- Volodymyr Nahirnyak
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45267-0586, USA
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28
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Abstract
Stroke is a major public health problem in the United States and the development of novel therapeutic strategies is an important research priority. Advances in this field are proceeding on several fronts, including the use of next-generation plasminogen activators and glycoprotein IIb/ IIIa inhibitors, refined patient selection with advanced magnetic resonance imaging sequences, endovascular approaches to thrombolysis and thrombectomy, and adjuvant use of ultrasound. There remains no proven therapy for intracerebral hemorrhage, but early results with recombinant activated factor VII look very promising. It is hoped that in the near future, physicians managing patients with acute neurological events will have a robust armamentarium of therapies to bring to bear on both ischemic and hemorrhagic vascular disease.
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Affiliation(s)
- Justin A Sattin
- Department of Neurosciences, San Diego School of Medicine, University of California, San Diego, CA, USA
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29
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Stone MJ, Frenkel V, Dromi S, Thomas P, Lewis RP, Li KCP, Horne M, Wood BJ. Pulsed-high intensity focused ultrasound enhanced tPA mediated thrombolysis in a novel in vivo clot model, a pilot study. Thromb Res 2007; 121:193-202. [PMID: 17481699 PMCID: PMC2169501 DOI: 10.1016/j.thromres.2007.03.023] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 03/08/2007] [Accepted: 03/09/2007] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Thrombotic disease continues to account for significant morbidity and mortality. Ultrasound energy has been investigated as a potential primary and adjunctive treatment for thrombotic disease. We have previously shown that pulsed-high intensity focused ultrasound (HIFU) enhances thrombolysis induced by tissue plasminogen activator (tPA) in vitro, including describing the non-destructive mechanism by which tPA availability and consequent activity are increased. In this study we aimed to determine if the same effects could be achieved in vivo. MATERIALS AND METHODS In this study, pulsed-HIFU exposures combined with tPA boluses were compared to treatment with tPA alone, HIFU alone and control in a novel in vivo clot model. Clots were formed in the rabbit marginal ear vein and verified using venography and infrared imaging. The efficacy of thrombolytic treatment was monitored via high resolution ultrasonography for 5 h post-treatment. The cross-sectional area of clots at 4 points along the vein was measured and normalized to the pre-treatment size. RESULTS At 5 h the complete recanalization of clots treated with pulsed-HIFU and tPA was significantly different from the partial recanalization seen with tPA treatment alone. tPA treatment alone showed a significant decrease in clot versus control, where HIFU was not significantly different than control. Histological analysis of the vessel walls in the treated veins showed no apparent irreversible damage to endothelial cells or extravascular tissue. CONCLUSIONS This study demonstrates that tPA mediated thrombolysis can be significantly enhanced when combined with non-invasive pulsed-HIFU exposures.
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Affiliation(s)
- Michael J. Stone
- Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
- Howard Hughes Medical Institute Research Scholars Program
| | - Victor Frenkel
- Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Sergio Dromi
- Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Peter Thomas
- Division of Bioengineering and Physical Science, Office of Research Services, National Institutes of Health, Bethesda, MD, USA
| | - Ryan P. Lewis
- Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - King CP Li
- Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - McDonald Horne
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Bradford J. Wood
- Diagnostic Radiology Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA
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