1
|
Wang H, Yan WH, Sun JJ, Dong M, Zhang N, Liu T, Song NP, Zhong L. An extranodal Richter's syndrome presenting with cardiac diffuse large B-cell lymphoma: a case report. BMC Cardiovasc Disord 2023; 23:624. [PMID: 38129785 PMCID: PMC10740268 DOI: 10.1186/s12872-023-03663-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND Richter's syndrome (RS) defines the transformation of chronic lymphocytic leukemia into high-grade lymphoma, which usually involves lymph nodes and bone marrow. Extranodal involvement of the heart is an extremely rare condition. Patients with heart involvement tended to have a low response to chemotherapy and relative poor prognosis. The transformation process of RS is often insidious and nonspecific making it challenging to diagnose. CASE PRESENTATION A 64-year-old woman wih a history of chronic lymphocytic leukemia (CLL) presented with intermittent chest pain and was diagnosed with non-ST-elevation myocardial infarction (NSTEMI). However, the contrast enhanced echocardiography revealed a large irregular mass, measuring about 75.4 mm × 37.5 mm, located on the lateral and posterior wall of the right ventricle. Biopsy of the cardiac mass and the results revealed diffuse large B-cell lymphoma. CONCLUSIONS We present a case of a 64-year-old woman with aggressive diffuse large B-cell lymphoma involving the heart. This case could provide some insights in the diagnosis of cardiac lymphoma.
Collapse
MESH Headings
- Female
- Humans
- Middle Aged
- Biopsy
- Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Lymphoma, Large B-Cell, Diffuse/complications
- Lymphoma, Large B-Cell, Diffuse/diagnosis
- Lymphoma, Large B-Cell, Diffuse/drug therapy
- Heart Neoplasms/diagnosis
- Heart Neoplasms/pathology
Collapse
Affiliation(s)
- Hua Wang
- Department of Cardiology, Yantai Yuhuangding Hospital, Qingdao Medical College, Qingdao University, No. 20 East Yuhuangding Road, Yantai, 264000, China
| | - Wei-Hong Yan
- Department of Cardiology, Yantai Yuhuangding Hospital, Qingdao Medical College, Qingdao University, No. 20 East Yuhuangding Road, Yantai, 264000, China
| | - Jun-Jie Sun
- Department of Ultrasound, Yantai Yuhuangding Hospital, Qingdao Medical College, Qingdao University, Yantai, China
| | - Mei Dong
- Department of Cardiology, Yantai Yuhuangding Hospital, Qingdao Medical College, Qingdao University, No. 20 East Yuhuangding Road, Yantai, 264000, China
| | - Nan Zhang
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Nian-Peng Song
- Department of Cardiology, Yantai Yuhuangding Hospital, Qingdao Medical College, Qingdao University, No. 20 East Yuhuangding Road, Yantai, 264000, China
| | - Lin Zhong
- Department of Cardiology, Yantai Yuhuangding Hospital, Qingdao Medical College, Qingdao University, No. 20 East Yuhuangding Road, Yantai, 264000, China.
| |
Collapse
|
2
|
|
3
|
Otani K, Kamiya A, Miyazaki T, Koga A, Inatomi A, Harada-Shiba M. Surface Modification with Lactadherin Augments the Attachment of Sonazoid Microbubbles to Glycoprotein IIb/IIIa. ULTRASOUND IN MEDICINE & BIOLOGY 2019; 45:1455-1465. [PMID: 30857759 DOI: 10.1016/j.ultrasmedbio.2019.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/07/2018] [Accepted: 01/25/2019] [Indexed: 06/09/2023]
Abstract
Arginine-glycine-aspartate (RGD)-carrying microbubbles (MBs) have been utilized as a specific contrast agent for glycoprotein IIb/IIIa (αIIbβ3 integrin)-expressing activated platelets in ultrasound molecular imaging. Recently, we found that surface modification with lactadherin provides the RGD motif on the surface of phosphatidylserine-containing clinically available MBs, Sonazoid. Here, we examined the potential of lactadherin-bearing Sonazoid MBs to be targeted MBs for glycoprotein IIb/IIIa using the custom-designed in vitro settings with recombinant αIIbβ3 integrin, activated platelets or erythrocyte-rich human clots. By modification of the surface with lactadherin, a large number of Sonazoid MBs were attached to the αIIbβ3 integrin-coated and platelet-immobilized plate. Additionally, the video intensity of clots after incubation with lactadherin-bearing Sonazoid MBs was significantly higher than that with unmodified Sonazoid MBs, implying the number of attached Sonazoid MBs was increased by the modification with lactadherin. Our results suggest that the lactadherin-bearing Sonazoid MBs have the potential to be thrombus-targeted MBs.
Collapse
Affiliation(s)
- Kentaro Otani
- Department of Regenerative Medicine and Tissue Engineering, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan.
| | - Atsunori Kamiya
- Department of Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takahiro Miyazaki
- Department of Cell Biology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Ayumi Koga
- Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Ayako Inatomi
- Department of Regenerative Medicine and Tissue Engineering, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Mariko Harada-Shiba
- Department of Regenerative Medicine and Tissue Engineering, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; Department of Molecular Innovation in Lipidology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| |
Collapse
|
4
|
Liao Y, Yang L, Huang R, Wu J, Xie J, Bundhoo K, Liu Y, Hu G, Liu C, Bin J. Ultrasound molecular imaging of arterial thrombi with novel microbubbles modified by cyclic RGD in vitro and in vivo. Thromb Haemost 2017; 107:172-83. [DOI: 10.1160/th10-11-0701] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 09/28/2011] [Indexed: 12/17/2022]
Abstract
SummaryDespite immense potential, ultrasound molecular imaging (UMI) of arterial thrombi remains very challenging because the high-shear arterial flow limits binding of site-targeted microbubbles to the thrombi. The linear Arg-Gly-Asp (RGD) peptides have been successfully applied to evaluate venous, atrial, and arteriolar thrombi, but have thus far failed in the detection of arterial thrombi. Cyclic RGD (Arg-Gly-Asp-D-Phe-Cys) is a cyclic conformation of linear RGD peptides, which has much higher binding-affinity and selectivity for binding to the glycoprotein (GP) IIb/IIIa receptor than its linear counterpart and thus is likely to be an optimal targeted molecular probe for ultrasound molecular imaging of arterial thrombi. In this study, we sought to assess the feasibility of a novel microbubble conjugated with cyclic RGD (Mb-cyclic RGD) in UMI of arterial thrombi in vitro and in vivo. As expected, Mb-cyclic RGD had greater GP IIb/IIIa-targeted binding capability in all shear stress conditions. In addition, the shear stress at half-maximal detachment of Mb-cyclic RGD was 5.7-fold higher than that of microbubbles with nonspecific peptide (Mb-CON) (p<0.05). Mb-cyclic RGD enhanced the echogenicity of the platelet-rich thrombus in vitro whereas Mb-CON did not produce enhancement. In the in vivo setting, optimal signal enhancement of the abdominal aortic thrombus was displayed with Mb-cyclic RGD in all cases. Mean video intensity of the abdominal aortic thrombi with Mb-cyclic RGD was 3.2-fold higher than that with Mb-CON (p<0.05). The novel Mb-cyclic RGD facilitated excellent visualisation of arterial thrombi using UMI and showed great promise for clinical applications.
Collapse
|
5
|
Guo S, Shen S, Wang J, Wang H, Li M, Liu Y, Hou F, Liao Y, Bin J. Detection of high-risk atherosclerotic plaques with ultrasound molecular imaging of glycoprotein IIb/IIIa receptor on activated platelets. Am J Cancer Res 2015; 5:418-30. [PMID: 25699100 PMCID: PMC4329504 DOI: 10.7150/thno.10020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 12/28/2014] [Indexed: 12/23/2022] Open
Abstract
Objective: Ultrasound molecular imaging (UMI) of glycoprotein (GP) IIb/IIIa receptor on activated platelets offers a unique means of identifying high-risk atherosclerosis. We hypothesized that contrast-enhanced ultrasound with microbubbles (MBs) targeted to GP IIb/IIIa could be used to detect and quantify activated platelets on the surface of advanced plaques. Methods and Results: A mouse model of advanced atherosclerosis was generated by maintaining apolipoprotein E-deficient (ApoE-/-) mice on a hypercholesterolemic diet (HCD). The three other experimental groups consisted of ApoE-/- and wild-type (C57BL/6) mice fed a normal chow diet and C57BL/6 mice on an HCD diet. Plaque formation was confirmed by histological and immunohistochemical methods using light, fluorescence, and electron microscopy. Mice were injected with a lipid MB-conjugated cyclic Arg-Gly-Asp peptide or nonspecific control peptide, and the abdominal aorta was examined by UMI. The accumulation of GP IIb/IIIa and activated platelets on the surface of atherosclerotic plaques was highest in the ApoE-/-+HCD group, followed by ApoE-/-+chow, C57BL/6+HCD, and C57BL/6+chow groups (P<0.05). Notably, GP IIb/IIIa expression was associated with the vulnerability index and necrotic center/fiber cap ratio (P<0.05), and contrast video intensity from adhered cyclic Arg-Gly-Asp-modified MBs (MB-cRGDs) was correlated with GP IIb/IIIa expression on the plaque surface (P<0.05). Conclusion: GP IIb/IIIa of activated platelets on the atherosclerotic endothelium is a biomarker for high-risk plaques that can be quantified by UMI using MB-cRGDs, providing a noninvasive means for detecting high-risk plaques and preventing acute cardiovascular events.
Collapse
|
6
|
Alonso A, Artemis D, Hennerici MG. Molecular imaging of carotid plaque vulnerability. Cerebrovasc Dis 2014; 39:5-12. [PMID: 25547782 DOI: 10.1159/000369123] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Carotid endarterectomy (CEA) has been shown to be beneficial in patients with high-grade symptomatic carotid artery stenosis. Patients with high-grade asymptomatic stenosis may only exceptionally benefit from CEA during periods of increased plaque vulnerability. Imaging modalities to characterize unstable, vulnerable plaques are strongly needed for better risk stratification in these patients. SUMMARY Contrast-enhanced ultrasound (CEUS) is a novel and noninvasive technique capable to identify several surrogate markers of vulnerable carotid plaques. The use of specific ultrasound microbubbles allows a reliable detection of microulcerations due to an optimized visualization of the plaque-lumen border. As microbubbles are strictly intravascular tracers, the detection of individual microbubbles within the plaque corresponds to intraplaque neovessels. The accuracy of CEUS in the visualization of newly formed microvessels has been confirmed in histological studies on carotid endarterectomy specimens. Together with the formation of adventitial vasa vasorum, intraplaque neovascularization is a strong predictor for symptomatic disease. The phenomenon of late phase contrast enhancement is based on the adherence of microbubble-containing monocytes on inflamed endothelium. Recent studies suggest that late phase contrast enhancement may reflect endothelial inflammation or activation within carotid plaques. The development of conjugated microbubbles that bind to specific ligands such as thrombotic material or neovessels has led to the term 'molecular imaging'. CEUS with microbubbles targeted to P-selectin and VCAM-1, key molecules in leukocyte trafficking, was used to detect an inflammatory plaque phenotype, whereas microbubbles coupled to the VEGF-receptor may allow for a detection of neovascularization. Even though imaging with targeted microbubbles is yet in an experimental stage, this technique can visualize active plaque reorganization with increased vulnerability leading to generation of arterio-arterial embolism. Key Messages: The use of contrast-enhanced ultrasound can be recommended to assess atherosclerotic carotid lesions at risk for rupture. Prospective clinical studies are needed to validate the use of CEUS in patients with high risks of recurrent large artery strokes. In particular, this applies to the detection of intraplaque neovascularization, a well-established marker in preclinical and observational studies, while the clinical significance of late phase contrast enhancement still needs to be determined..
Collapse
Affiliation(s)
- Angelika Alonso
- Department of Neurology, Universitätsmedizin Mannheim, University of Heidelberg, Germany
| | | | | |
Collapse
|
7
|
In vivo ultrasound molecular imaging of inflammatory thrombosis in arteries with cyclic Arg-Gly-Asp-modified microbubbles targeted to glycoprotein IIb/IIIa. Invest Radiol 2014; 48:803-12. [PMID: 23857134 DOI: 10.1097/rli.0b013e318298652d] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Ultrasound molecular imaging has the potential to detect activated platelets, thus identifying atherosclerotic plaque instability before onset of serious clinical events. However, it has not been well defined in inflammatory arterial thrombosis. We hypothesized that microbubbles (MBs) target glycoprotein IIb/IIIa (GP IIb/IIIa) could achieve a noninvasive in vivo detection of inflammatory thrombosis in large arteries through contrast-enhanced ultrasound (CEU) imaging. MATERIALS AND METHODS Lipid shell-based gas-filled MBs were modified covalently with a cyclic Arg-Gly-Asp (RGD) peptide (MB-cRGD) targeted to activated GP IIb/IIIa or a negative control peptide (MB-CON) via thiol-maleimide coupling. Adherence of MB-cRGD and MB-CON to GP IIb/IIIa was determined in vitro by using a parallel plate flow chamber at variable shear stress (0.5-8 dynes/cm2). Inflammatory platelet thrombosis was induced by periadvential application of arachidonic acid (AA) to one of the bilateral carotids of C57BL/6 mice (n = 20) and confirmed through intravital fluorescence microscopy. Attachment of MBs was determined in vivo with CEU imaging of bilateral carotids in the AA application mice with (n = 10) or without (n = 10) pretreatment of GP IIb/IIIa antagonist. The expression of integrin GP IIb/IIIa was assessed through immunohistochemistry. RESULTS Microbubble-cRGD but not MB-CON had excellent affinity to GP IIb/IIIa under all shear stress conditions. Successful inflammatory platelet activation and thrombosis in AA application carotids were noted through intravital fluorescence microscopy. Contrast video intensity from adhered MB-cRGD in the thrombi was significantly higher than that from MB-CON (P < 0.05). Video intensity of MB-cRGD in the thrombi was suppressed significantly by preblocking with GP IIb/IIIa antagonist (P < 0.05) but not for MB-CON. Immunohistochemical finding demonstrates that expression of integrin GP IIb/IIIa in the thrombi was abundant; it was inhibited significantly through pretreatment with GP IIb/IIIa antagonist (P < 0.05). CONCLUSIONS Cyclic RGD-modified MBs targeted to GP IIb/IIIa with CEU are capable of detecting inflammation-activated platelets and thrombosis in large arteries, thus providing a potential tool for identification of vulnerable atherosclerotic plaques.
Collapse
|
8
|
Xu WM, Feng M, Zhao HY, Xie MX, Li WY, Fu R. Preparation of thrombosis-targeted lipid microbubbles and determination of rabbit carotid artery thrombosis by microbubbles ultrasonogaphy. ACTA ACUST UNITED AC 2013; 33:146-152. [DOI: 10.1007/s11596-013-1088-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Indexed: 10/27/2022]
|
9
|
Wadajkar AS, Santimano S, Rahimi M, Yuan B, Banerjee S, Nguyen KT. Deep vein thrombosis: current status and nanotechnology advances. Biotechnol Adv 2012; 31:504-513. [PMID: 22940402 DOI: 10.1016/j.biotechadv.2012.08.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 08/13/2012] [Accepted: 08/14/2012] [Indexed: 12/12/2022]
Abstract
Deep vein thrombosis (DVT) affects up to 2 million people in the United States, and worldwide incidence is 70 to 113 cases per 100,000 per year. Mortality from DVT is often due to subsequent pulmonary embolism (PE). Precise diagnosis and treatment is thereby essential for the management of DVT. DVT is diagnosed by a thorough history and physical examination followed by laboratory and diagnostic tests. The choice of laboratory and diagnostic test is dependent on clinical pretest probability. Available laboratory and diagnostic techniques mainly involve D-dimer test, ultrasound, venography, and magnetic resonance imaging. The latter two diagnostic tools require high doses of contrast agents including either radioactive or toxic materials. The available treatment options include lifestyle modifications, mechanical compression, anticoagulant therapy, inferior vena cava filter, and thrombolysis/thrombolectomy. All of these medical and surgical treatments have serious side effects including improper clot clearance and increased risk of hemorrhage occurrence. Therefore, research in this field has recently focused on the development of non-invasive and accurate diagnostics, such as ultrasound enhanced techniques and molecular imaging methods, to assess thrombus location and its treatment course. The frontier of nanomedicine also shows high prospects in tackling DVT with efficient targeted drug delivery. This review describes the pathology of DVT along with successive medical problems such as PE and features a detailed listing of various diagnostic and therapeutic modalities that have been in use and are under development.
Collapse
Affiliation(s)
- Aniket S Wadajkar
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA
- Joint Biomedical Engineering Program between The University of Texas at Arlington and The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sonia Santimano
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA
- Joint Biomedical Engineering Program between The University of Texas at Arlington and The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Maham Rahimi
- Department of Vascular Surgery, University of Cincinnati, OH 45267, USA
| | - Baohong Yuan
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA
- Joint Biomedical Engineering Program between The University of Texas at Arlington and The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Subhash Banerjee
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kytai T Nguyen
- Department of Bioengineering, The University of Texas at Arlington, Arlington, TX 76019, USA
- Joint Biomedical Engineering Program between The University of Texas at Arlington and The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| |
Collapse
|
10
|
Wang X, Hagemeyer CE, Hohmann JD, Leitner E, Armstrong PC, Jia F, Olschewski M, Needles A, Peter K, Ahrens I. Novel single-chain antibody-targeted microbubbles for molecular ultrasound imaging of thrombosis: validation of a unique noninvasive method for rapid and sensitive detection of thrombi and monitoring of success or failure of thrombolysis in mice. Circulation 2012; 125:3117-26. [PMID: 22647975 DOI: 10.1161/circulationaha.111.030312] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Molecular imaging is a fast emerging technology allowing noninvasive detection of vascular pathologies. However, imaging modalities offering high resolution currently do not allow real-time imaging. We hypothesized that contrast-enhanced ultrasound with microbubbles (MBs) selectively targeted to activated platelets would offer high-resolution, real-time molecular imaging of evolving and dissolving arterial thrombi. METHODS AND RESULTS Lipid-shell based gas-filled MBs were conjugated to either a single-chain antibody specific for activated glycoprotein IIb/IIIa via binding to a Ligand-Induced Binding Site (LIBS-MBs) or a nonspecific single-chain antibody (control MBs). Successful conjugation was assessed in flow cytometry and immunofluorescence double staining. LIBS-MBs but not control MBs strongly adhered to both immobilized activated platelets and microthrombi under flow. Thrombi induced in carotid arteries of C57Bl6 mice in vivo by ferric chloride injury were then assessed with ultrasound before and 20 minutes after MB injection through the use of gray-scale area intensity measurement. Gray-scale units converted to decibels demonstrated a significant increase after LIBS-MB but not after control MB injection (9.55±1.7 versus 1.46±1.3 dB; P<0.01). Furthermore, after thrombolysis with urokinase, LIBS-MB ultrasound imaging allows monitoring of the reduction of thrombus size (P<0.001). CONCLUSION We demonstrate that glycoprotein IIb/IIIa-targeted MBs specifically bind to activated platelets in vitro and allow real-time molecular imaging of acute arterial thrombosis and monitoring of the success or failure of pharmacological thrombolysis in vivo.
Collapse
Affiliation(s)
- Xiaowei Wang
- Atherothrombosis and Vascular Biology, Baker IDI Heart and Diabetes Institute, PO Box 6492, St. Kilda Rd Central, Victoria 8008, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Nanobody-coupled microbubbles as novel molecular tracer. J Control Release 2011; 158:346-53. [PMID: 22197777 DOI: 10.1016/j.jconrel.2011.12.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Revised: 12/05/2011] [Accepted: 12/07/2011] [Indexed: 11/21/2022]
Abstract
Camelid-derived single-domain antibody-fragments (~15kDa), called nanobodies, are a new class of molecular tracers that are routinely identified with nanomolar affinity for their target and that are easily tailored for molecular imaging and drug delivery applications. We hypothesized that they are well-suited for the design of targeted microbubbles (μBs) and aimed to develop and characterize eGFP- and VCAM-1-targeted μBs. Anti-eGFP (cAbGFP4) and anti-VCAM-1 (cAbVCAM1-5) nanobodies were site-specifically biotinylated in bacteria. This metabolic biotinylation method yielded functional nanobodies with one biotin located at a distant site of the antigen-binding region of the molecule. The biotinylated nanobodies were coupled to biotinylated lipid μBs via streptavidin-biotin bridging. The ability of μB-cAbGFP4 to recognize eGFP was tested as proof-of-principle by fluorescent microscopy and confirmed the specific binding of eGFP to μB-cAbGFP4. Dynamic flow chamber studies demonstrated the ability of μB-cAbVCAM1-5 to bind VCAM-1 in fast flow (up to 5 dynes/cm(2)). In vivo targeting studies were performed in MC38 tumor-bearing mice (n=4). μB-cAbVCAM1-5 or control μB-cAbGFP4 were injected intravenously and imaged using a contrast-specific ultrasound imaging mode. The echo intensity in the tumor was measured 10min post-injection. μB-cAbVCAM1-5 showed an enhanced signal compared to control μBs (p<0.05). Using metabolic and site-specific biotinylation of nanobodies, a method to develop nanobody-coupled μBs was described. The application of VCAM-1-targeted μBs as novel molecular ultrasound contrast agent was demonstrated both in vitro and in vivo.
Collapse
|
12
|
Hagisawa K, Nishioka T, Suzuki R, Takizawa T, Maruyama K, Takase B, Ishihara M, Kurita A, Yoshimoto N, Ohsuzu F, Kikuchi M. Enhancement of ultrasonic thrombus imaging using novel liposomal bubbles targeting activated platelet glycoprotein IIb/IIIa complex—in vitro and in vivo study. Int J Cardiol 2011; 152:202-6. [DOI: 10.1016/j.ijcard.2010.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 06/19/2010] [Accepted: 07/04/2010] [Indexed: 10/19/2022]
|
13
|
Sonoporation of endothelial cells by vibrating targeted microbubbles. J Control Release 2011; 154:35-41. [PMID: 21514333 DOI: 10.1016/j.jconrel.2011.04.008] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 04/01/2011] [Accepted: 04/06/2011] [Indexed: 12/20/2022]
Abstract
Molecular imaging using ultrasound makes use of targeted microbubbles. In this study we investigated whether these microbubbles could also be used to induce sonoporation in endothelial cells. Lipid-coated microbubbles were targeted to CD31 and insonified at 1 MHz at low peak negative acoustic pressures at six sequences of 10 cycle sine-wave bursts. Vibration of the targeted microbubbles was recorded with the Brandaris-128 high-speed camera (~13 million frames per second). In total, 31 cells were studied that all had one microbubble (1.2-4.2 micron in diameter) attached per cell. After insonification at 80 kPa, 30% of the cells (n=6) had taken up propidium iodide, while this was 20% (n=1) at 120 kPa and 83% (n=5) at 200 kPa. Irrespective of the peak negative acoustic pressure, uptake of propidium iodide was observed when the relative vibration amplitude of targeted microbubbles was greater than 0.5. No relationship was found between the position of the microbubble on the cell and induction of sonoporation. This study shows that targeted microbubbles can also be used to induce sonoporation, thus making it possible to combine molecular imaging and drug delivery.
Collapse
|
14
|
Molecular sonography with targeted microbubbles: current investigations and potential applications. Ultrasound Q 2010; 26:75-82. [PMID: 20498563 DOI: 10.1097/ruq.0b013e3181df96de] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Sonography using targeted microbubbles affords a variety of diagnostic and potentially therapeutic clinical applications. It provides a whole new world of functional information at the cellular and molecular level. This information can then be used to diagnose and possibly prevent diseases at early stages as well as devise therapeutic strategies at the molecular level. It is also useful in monitoring tumor response to therapy and devising treatment timing and plans based on the molecular state of an individual's health. Moreover, targeted microbubble-enhanced sonography has several advantages over other imaging modalities, including widespread availability, low cost, fast acquisition times, and lack of radiation risk. These traits are likely to advance it as one of the imaging methods of choice in future clinical trials examining the impact of molecular imaging on treatment outcome. This review describes the fundamental concepts of targeted microbubble-enhanced sonography as well as its potential clinical applications.
Collapse
|
15
|
Abstract
Noninvasive cardiovascular imaging techniques are well-established for studying cardiovascular anatomy and physiology. Over the past decade contrast enhanced imaging techniques have been developed that are also able to characterize the molecular constituents of cardiovascular disease. In this regard, microbubble- and ultrasound-based techniques have the ability to assess a broad range of molecular components of cardiovascular pathology such as inflammation, recent ischemia, atherosclerosis, acute transplant rejection, angiogenesis, and thrombosis. The advantages of ultrasound- and microbubble-based approach include the ability to assess multiple molecular disease markers without exposure to ionizing radiation or prolonged imaging protocols. This review highlights the development of microbubble-based molecular imaging, describes successful experimental conditions in which they have been studied, and postulates the importance of translating this technique into the clinical practice.
Collapse
Affiliation(s)
- Scott M Chadderdon
- Cardiovascular Division, UHN 62, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | | |
Collapse
|
16
|
Abstract
Ultrasound is a very effective modality for drug delivery and gene therapy because energy that is non-invasively transmitted through the skin can be focused deeply into the human body in a specific location and employed to release drugs at that site. Ultrasound cavitation, enhanced by injected microbubbles, perturbs cell membrane structures to cause sonoporation and increases the permeability to bioactive materials. Cavitation events also increase the rate of drug transport in general by augmenting the slow diffusion process with convective transport processes. Drugs and genes can be incorporated into microbubbles, which in turn can target a specific disease site using ligands such as the antibody. Drugs can be released ultrasonically from microbubbles that are sufficiently robust to circulate in the blood and retain their cargo of drugs until they enter an insonated volume of tissue. Local drug delivery ensures sufficient drug concentration at the diseased region while limiting toxicity for healthy tissues. Ultrasound-mediated gene delivery has been applied to heart, blood vessel, lung, kidney, muscle, brain, and tumour with enhanced gene transfection efficiency, which depends on the ultrasonic parameters such as acoustic pressure, pulse length, duty cycle, repetition rate, and exposure duration, as well as microbubble properties such as size, gas species, shell material, interfacial tension, and surface rigidity. Microbubble-augmented sonothrombolysis can be enhanced further by using targeting microbubbles.
Collapse
Affiliation(s)
- H-D Liang
- School of Engineering, Cardiff University, Cardiff, UK.
| | | | | |
Collapse
|
17
|
Santin MD, King DA, Foiret J, Haak A, O'Brien WD, Bridal SL. Encapsulated contrast microbubble radial oscillation associated with postexcitation pressure peaks. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2010; 127:1156-64. [PMID: 20136236 PMCID: PMC2852442 DOI: 10.1121/1.3277216] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This work combines modeling and experiment to assess encapsulated microbubble oscillations associated with broadband pressure peaks detected after microbubble excitation (postexcitation signals). Data were acquired from albumin-shelled and phospholipid-shelled microbubbles using a passive cavitation detector consisting of a confocally aligned 2.8-MHz transmitter and 13-MHz receiver. Microbubbles in weak solutions were insonified with a 5-cycle pulse at a peak rarefactional pressure of 2.0+/-0.2 MPa. For each microbubble type, at least 100 received signals were identified as individual-microbubble responses. The average broadband noise from signals with postexcitation response was 4.2-7.2 dB higher than from signals without postexcitation. Pressure-time responses for each microbubble type were simulated using the model by Marmottant et al. [J. Acoust. Soc. Am. 118, 3499-3505 (2005)], with insonification conditions matching the experiment. Increased broadband noise predicted for microbubbles with postexcitation response was consistent with that observed experimentally (4.0-8.9 dB). The model predicted that postexcitation signals occur only when the radial oscillation exceeds both the shell break-up threshold and twice the initial radius (free bubble inertial cavitation threshold).
Collapse
Affiliation(s)
- M D Santin
- UPMC Univ Paris 06, UMR 7623, LIP, F-75005 Paris, France
| | | | | | | | | | | |
Collapse
|
18
|
Tinkov S, Bekeredjian R, Winter G, Coester C. Microbubbles as ultrasound triggered drug carriers. J Pharm Sci 2009; 98:1935-61. [PMID: 18979536 DOI: 10.1002/jps.21571] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Originally developed as contrast agents for ultrasound imaging and diagnostics, in the past years, microbubbles have made their way back from the patients' bedside to the researcher's laboratory. Microbubbles are currently believed to have great potential as carriers for drugs, small molecules, nucleic acids, and proteins. This review provides insight into this intriguing new frontier from the perspective of the pharmaceutical scientist. First, basic aspects on the application of ultrasound-targeted microbubble destruction for drug delivery will be presented. Next, we will review the recently applied approaches for manufacturing and drug-loading microbubbles. Important quality issues and characterization techniques for advanced microbubble formulation will be discussed. Finally, we will provide an assessment of the prospects for microbubbles in drug and gene therapy, illustrating the problems and requirements for their future development.
Collapse
Affiliation(s)
- Steliyan Tinkov
- Department of Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians University-Munich, Butenandtstr. 5-13, D-81377 Munich, Germany
| | | | | | | |
Collapse
|
19
|
Molecular imaging: a primer for interventionalists and imagers. J Vasc Interv Radiol 2009; 20:S505-22. [PMID: 19560036 DOI: 10.1016/j.jvir.2009.04.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 06/15/2006] [Accepted: 06/19/2006] [Indexed: 12/14/2022] Open
Abstract
The characterization of human diseases by their underlying molecular and genomic aberrations has been the hallmark of molecular medicine. From this, molecular imaging has emerged as a potentially revolutionary discipline that aims to visually characterize normal and pathologic processes at the cellular and molecular levels within the milieu of living organisms. Molecular imaging holds promise to provide earlier and more precise disease diagnosis, improved disease characterization, and timely assessment of therapeutic response. This primer is intended to provide a broad overview of molecular imaging with specific focus on future clinical applications relevant to interventional radiology.
Collapse
|
20
|
Abstract
Techniques for noninvasive imaging of specific disease-related molecular changes are being developed to enhance diagnosis and therapeutic decision making in the clinical setting, and to facilitate research efforts. Molecular imaging with contrast-enhanced ultrasonography relies on the detection of the acoustic signal produced by microbubble or nanoparticle agents that are targeted to sites of disease. This Review describes the basis for ultrasound molecular imaging, the unique features of contrast agent behavior or detector performance in relation to clinical or research needs, and the progress that has been made to date in imaging key events in cardiovascular medicine, such as atherosclerosis, postischemic inflammation, angiogenesis, transplant rejection and thrombus formation.
Collapse
|
21
|
Piedra M, Allroggen A, Lindner JR. Molecular imaging with targeted contrast ultrasound. Cerebrovasc Dis 2009; 27 Suppl 2:66-74. [PMID: 19372662 DOI: 10.1159/000203128] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Molecular imaging with contrast-enhanced ultrasound uses targeted microbubbles that are retained in diseased tissue. The resonant properties of these microbubbles produce acoustic signals in an ultrasound field. The microbubbles are targeted to diseased tissue by using certain chemical constituents in the microbubble shell or by attaching disease-specific ligands such as antibodies to the microbubble. In this review, we discuss the applications of this technique to pathological states in the cerebrovascular system including atherosclerosis, tumor angiogenesis, ischemia, intravascular thrombus, and inflammation.
Collapse
Affiliation(s)
- Mark Piedra
- Division of Cardiovascular Medicine, Oregon Health and Science University, Portland, OR 97239, USA
| | | | | |
Collapse
|
22
|
Abstract
The successful use of targeted ultrasound contrast agents (USCAs) for qualitative US-based imaging has been shown by several academic and industrial research groups in different animal models. Furthermore, techniques have been developed that enable the in-vivo quantification of targeted microbubbles (MBs). USCAs for quantitative functional and molecular imaging in small animals can be used for a more detailed characterization of new and established disease models and provide quantitative biological insights into the interaction between drug and target or target and disease in living animals. The advantages of such contrast agents in research and development are seen to be as follows: new functional or molecular findings in the complex biology of disease development, these findings can lead to new therapeutic strategies or drug candidates, a better understanding of the treatment effects of new and existing drug candidates, a more sensitive and specific characterization of early treatment effects in living animals, identification of in-vivo biomarkers for translational medicine. Further outcomes are seen in speeding up the evaluation of new drug compounds and in a reduction of the number of animals used for biomedical research.
Collapse
Affiliation(s)
- Peter Hauff
- Global Drug Discovery, Bayer Schering Pharma AG, 13342, Berlin, Germany.
| | | | | |
Collapse
|
23
|
Kawabata KI, Asami R, Azuma T, Yoshikawa H, Umemura SI. 2A-3 Enhanced and Site-Specific HIFU Treatment with Phase-Change Nano Droplet. ACTA ACUST UNITED AC 2007. [DOI: 10.1109/ultsym.2007.17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
24
|
Sassaroli E, Hynynen K. Cavitation threshold of microbubbles in gel tunnels by focused ultrasound. ULTRASOUND IN MEDICINE & BIOLOGY 2007; 33:1651-60. [PMID: 17590501 PMCID: PMC2078601 DOI: 10.1016/j.ultrasmedbio.2007.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2006] [Revised: 04/20/2007] [Accepted: 04/26/2007] [Indexed: 05/11/2023]
Abstract
The investigation of inertial cavitation in micro-tunnels has significant implications for the development of therapeutic applications of ultrasound such as ultrasound-mediated drug and gene delivery. The threshold for inertial cavitation was investigated using a passive cavitation detector with a center frequency of 1 MHz. Micro-tunnels of various diameters (90 to 800 microm) embedded in gel were fabricated and injected with a solution of Optison(trade mark) contrast agent of concentrations 1.2% and 0.2% diluted in water. An ultrasound pulse of duration 500 ms and center frequency 1.736 MHz was used to insonate the microbubbles. The acoustic pressure was increased at 1-s intervals until broadband noise emission was detected. The pressure threshold at which broadband noise emission was observed was found to be dependent on the diameter of the micro-tunnels, with an average increase of 1.2 to 1.5 between the smallest and the largest tunnels, depending on the microbubble concentration. The evaluation of inertial cavitation in gel tunnels rather than tubes provides a novel opportunity to investigate microbubble collapse in a situation that simulates in vivo blood vessels better than tubes with solid walls do.
Collapse
Affiliation(s)
- Elisabetta Sassaroli
- Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | | |
Collapse
|
25
|
Martin MJ, Chung EML, Goodall AH, Della Martina A, Ramnarine KV, Fan L, Hainsworth SV, Naylor AR, Evans DH. Enhanced Detection of Thromboemboli With the Use of Targeted Microbubbles. Stroke 2007; 38:2726-32. [PMID: 17823379 DOI: 10.1161/strokeaha.107.489435] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Targeted ultrasound contrast agents have recently been developed to adhere selectively to specific pathogenic materials such as plaque or thrombus. Administration of such microbubbles has potential to aid transcranial Doppler ultrasound (TCD) detection of emboli and to act as markers for distinguishing one embolic material from another. The purpose of this study was to investigate whether TCD detection of circulating thrombus emboli would be enhanced by the addition of targeted microbubbles.
Methods—
Binding of microbubbles to the surface of the thrombus was confirmed by scanning electron microscopy. Targeted and control bubbles were then introduced to thrombus and tissue-mimicking material circulated under pulsatile-flow conditions in an in vitro flow rig. Embolic signal intensities before and after introduction of the bubbles were measured by TCD.
Results—
Targeted microbubbles enhanced TCD signal intensities from thrombus emboli by up to 13 dB. The bubbles were capable of binding to moving thrombus when injected into the flow circuit in low concentrations (≈36 bubbles per 100 mL) and were retained on the thrombus under pulsatile-flow conditions. Signal intensities from similarly sized pieces of tissue-mimicking material were not enhanced by injection of targeted bubbles.
Conclusions—
Injection of appropriately targeted microbubbles significantly enhances TCD detection of circulating thrombus emboli in vitro.
Collapse
Affiliation(s)
- Matthew J Martin
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Alonso A, Della Martina A, Stroick M, Fatar M, Griebe M, Pochon S, Schneider M, Hennerici M, Allémann E, Meairs S. Molecular Imaging of Human Thrombus With Novel Abciximab Immunobubbles and Ultrasound. Stroke 2007; 38:1508-14. [PMID: 17379828 DOI: 10.1161/strokeaha.106.471391] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Molecular imaging of therapeutic interventions with targeted agents that simultaneously carry drugs or genes for local delivery is appealing. We investigated the ability of a novel microbubble carrier (immunobubble) for abciximab, a glycoprotein IIb/IIIa receptor inhibitor, for ultrasonographic molecular imaging of human clots.
Methods—
Human thrombi were incubated with immunobubbles conjugated with abciximab. Control clots were incubated in either saline or with immunobubbles conjugated with nonspecific antibody. We evaluated immunobubble suspensions with variable concentrations of encapsulated gas and measured mean acoustic intensity of the incubated clots. In vivo molecular imaging of human thrombi with abciximab immunobubbles was evaluated in a rat model of carotid artery occlusion.
Results—
Mean acoustic intensity was significantly higher for abciximab immunobubbles as compared with control immunobubbles under all conditions tested with maximum difference in intensity at a gas volume of 0.2 μL (
P
=0.0013 for mechanical index 0.05,
P
=0.0001 for mechanical index 0.7). Binding of abciximab immunobubbles to clots in vitro led to enhanced echogenicity dependent on bubble concentration. In vivo ultrasonic detectability of carotid thrombi was significantly higher for clots targeted with abciximab immunobubbles (
P
<0.05). Quantification of in vivo contrast enhancement displayed a highly significant increment for abciximab immunobubble-targeted clots compared with nonspecific immunobubble-targeted clots (
P
<0.0001) and to native clots (
P
<0.0001).
Conclusions—
This study demonstrates the feasibility of using a therapeutic agent for selective targeting in vascular imaging. Abciximab immunobubbles improve visualization of human clots both in vitro and in an in vivo model of acute arterial thrombotic occlusion.
Collapse
Affiliation(s)
- Angelika Alonso
- Department of Neurology, Universitätsklinikum Mannheim, University of Heidelberg, Heidelberg, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
Over the past three decades, echocardiography has become a major diagnostic tool in the arsenal of clinical cardiology for real-time imaging of cardiac dynamics. More and more, cardiologists' decisions are based on images created from ultrasound wave reflections. From the time ultrasound imaging technology provided the first insight into a human heart, our diagnostic capabilities have increased exponentially as a result of our growing knowledge and developing technologies. One of the most intriguing developments that brought about a decade-long combination of expectations and disappointments was the introduction of echocardiographic contrast agents. Despite repeated waves of controversy regarding the readiness of this technology for clinical use, it has overcome multiple hurdles and currently provides useful clinical information that helps cardiologists to diagnose heart disease accurately. Since the initial reports on the use of ultrasound contrast media such as agitated saline or renografin, the major advances in the field of contrast echocardiography have included (1) the development of stable perfluorocarbon-filled microbubbles, frequently referred to as second-generation contrast agents; and (2) the development of contrast-targeted nonlinear imaging modes, such as harmonic imaging, pulse inversion, and power modulation, which allow consistent real-time visualization of these agents. These contrast agents in conjunction with the new imaging technology constitute powerful tools that improve our ability to evaluate left ventricular function and myocardial perfusion, and allow differential diagnosis of thrombi and intravascular masses. In this manuscript, we briefly review some of the literature that has provided the scientific basis for the use of echocardiographic contrast agents in the context of these important variables.
Collapse
Affiliation(s)
- Roberto M Lang
- Cardiac Imaging Center, Department of Medicine, University of Chicago Medical Center, Illinois, USA.
| | | |
Collapse
|
28
|
Wang DS, Dake MD, Park JM, Kuo MD. Molecular Imaging: A Primer for Interventionalists and Imagers. J Vasc Interv Radiol 2006; 17:1405-23. [PMID: 16990461 DOI: 10.1097/01.rvi.0000235746.86332.df] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The characterization of human diseases by their underlying molecular and genomic aberrations has been the hallmark of molecular medicine. From this, molecular imaging has emerged as a potentially revolutionary discipline that aims to visually characterize normal and pathologic processes at the cellular and molecular levels within the milieu of living organisms. Molecular imaging holds promise to provide earlier and more precise disease diagnosis, improved disease characterization, and timely assessment of therapeutic response. This primer is intended to provide a broad overview of molecular imaging with specific focus on future clinical applications relevant to interventional radiology.
Collapse
Affiliation(s)
- David S Wang
- Department of Radiology and Center for Translational Medical Systems, University of California San Diego Medical Center, San Diego, CA 92103, USA
| | | | | | | |
Collapse
|
29
|
Wang B, Zang WJ, Wang M, Ai H, Wang YW, Li YP, He GS, Wang L, Yu XJ. Prolonging the ultrasound signal enhancement from thrombi using targeted microbubbles based on sulfur-hexafluoride-filled gas. Acad Radiol 2006; 13:428-33. [PMID: 16554222 DOI: 10.1016/j.acra.2005.11.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 11/15/2005] [Accepted: 11/15/2005] [Indexed: 10/24/2022]
Abstract
RATIONALE AND OBJECTIVES The objective of this study is to develop and characterize new microbubbles based on lipids and sulfur hexafluoride (SF6) for targeting thrombi as an improved ultrasound contrast agent. MATERIALS AND METHODS Bioconjugate ligands were inserted into the lipid-coated membranes of SF6 gas microbubbles, and their physicochemical properties were determined. Diagnostic efficacies of SF6-filled microbubbles and the contrast agent SonoVue (Bracco Imaging, Geneve, Switzerland) were compared in dogs. RESULTS Suspensions of lyophilized powder were reconstituted by injecting saline containing 3.1 x 10(8) SF6 microbubbles/mL with a mean diameter of 4.4 microm. More than 90% of microbubbles had diameters between 1 and 10 microm. After reconstitution, echogenicity and microbubble characteristics were unchanged for 8 hours. Targeted microbubbles increased the echogenicity of thrombi significantly and provided a longer period of optimal signal enhancement compared with nontargeted microbubbles. CONCLUSIONS Our thrombus-targeting microbubble contrast agent shows high echogenicity and stability and thereby enhances the visualization of intravascular thrombi and prolongs the duration of the diagnostic window.
Collapse
Affiliation(s)
- Bing Wang
- Department of Pathology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Sassaroli E, Hynynen K. Resonance frequency of microbubbles in small blood vessels: a numerical study. Phys Med Biol 2005; 50:5293-305. [PMID: 16264254 DOI: 10.1088/0031-9155/50/22/006] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Microbubbles are currently used as ultrasound contrast agents. Their potential therapeutic applications are also under investigation. This work is designed to provide some insight into the mechanisms of energy absorption and deposition by a preformed gas bubble in the microvasculature to optimize its efficacy. In the linear regime, the most favourable condition for the transfer of energy from an ultrasonic field to a gas bubble occurs when the centre frequency of the ultrasonic field equals the resonance frequency of the bubble. The resonance frequency of gas microbubbles has been investigated up to now mainly in unbounded liquids; however when bubbles are confined in small regions, their resonance frequency is strongly affected by the surrounding boundaries. A parametric study on how the resonance frequency of microbubbles in blood vessels is affected by the bubble radius, vessel radius and the bubble position in the vessel is presented. The resonance frequency decreases below its free value with decreasing vessel radius for vessels smaller than 200-300 microm depending on the bubble size. This model suggests the possibility of using ultrasound in a range of frequencies that are, in general, lower than the ones used now for therapeutic and diagnostic applications of ultrasound (a few MHz). When microbubbles oscillate at their resonance frequency they absorb and therefore emit more energy. This energy may allow specific blood vessels to be targeted for both diagnostic and therapeutic applications of ultrasound.
Collapse
Affiliation(s)
- E Sassaroli
- Focused Ultrasound Laboratory, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave, Boston, MA 02115, USA
| | | |
Collapse
|
31
|
Zhao S, Borden M, Bloch SH, Kruse D, Ferrara KW, Dayton PA. Radiation-force assisted targeting facilitates ultrasonic molecular imaging. Mol Imaging 2005. [PMID: 15530249 DOI: 10.1162/1535350042380317] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Ultrasonic molecular imaging employs contrast agents, such as microbubbles, nanoparticles, or liposomes, coated with ligands specific for receptors expressed on cells at sites of angiogenesis, inflammation, or thrombus. Concentration of these highly echogenic contrast agents at a target site enhances the ultrasound signal received from that site, promoting ultrasonic detection and analysis of disease states. In this article, we show that acoustic radiation force can be used to displace targeted contrast agents to a vessel wall, greatly increasing the number of agents binding to available surface receptors. We provide a theoretical evaluation of the magnitude of acoustic radiation force and show that it is possible to displace micron-sized agents physiologically relevant distances. Following this, we show in a series of experiments that acoustic radiation force can enhance the binding of targeted agents: The number of biotinylated microbubbles adherent to a synthetic vessel coated with avidin increases as much as 20-fold when acoustic radiation force is applied; the adhesion of contrast agents targeted to alpha(v)beta3 expressed on human umbilical vein endothelial cells increases 27-fold within a mimetic vessel when radiation force is applied; and finally, the image signal-to-noise ratio in a phantom vessel increases up to 25 dB using a combination of radiation force and a targeted contrast agent, over use of a targeted contrast agent alone.
Collapse
Affiliation(s)
- Shukui Zhao
- Department of Biomedical Engineering, University of California-Davis, USA
| | | | | | | | | | | |
Collapse
|
32
|
Bian AN, Gao YH, Tan KB, Liu P, Zeng GJ, Zhang X, Liu Z. Preparation of human hepatocellular carcinoma-targeted liposome microbubbles and their immunological properties. World J Gastroenterol 2004; 10:3424-7. [PMID: 15526360 PMCID: PMC4576222 DOI: 10.3748/wjg.v10.i23.3424] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To prepare the human hepatocellular carcinoma-(HCC)-targeted liposome microbubbles and to investigate their immunological properties.
METHODS: Human hepatocarcinoma specific monoclonal antibody HAb18 was attached to the surface of home-made liposome microbubbles by static attraction to prepare the targeted liposome microbubbles. The combination of HAb18 with liposome microbubbles was confirmed by the slide agglutination test and immunofluorescent assay. Their immunological activity was measured by ELISA. Rosette formation test, rosette formation blocking test and immun-ofluorescent assay were used to identify the specific binding of targeted liposome microbubbles to SMMC-7721 hepatoma cells, and cytotoxicity assay was used to detect their effect on human hepatocytes.
RESULTS: The targeted liposome microbubbles were positive in the slide agglutination test and immunofluorescent assay. ELISA indicated that the immunological activity of HAb18 on the liposome microbubbles was similar to that of free HAb18. SMMC-7721 cells were surrounded by the targeting liposome microbubbles to form rosettes, while the control SGC-7901 gastric cancer cells were not. Proliferation of SMMC-7721 cells and normal human hepatocytes was not influenced by the targeted liposome microbubbles.
CONCLUSION: The targeted liposome microbubbles with a high specific biological activity have been successfully prepared, which specifically bind to human hepatocarcinoma cells, and are non-cytotoxic to hepatocytes. These results indicate that the liposome microbubbles can be used as a HCC-targeted ultrasound contrast agent that may enhance ultrasound images and thus improve the diagnosis of HCC, especially at the early stage.
Collapse
Affiliation(s)
- Ai-Na Bian
- Department of Ultrasonic Diagnosis, Xinqiao Hospital, the Third Military Medical University, Chongqing 400037, China
| | | | | | | | | | | | | |
Collapse
|
33
|
Affiliation(s)
- Susannah H Bloch
- Department of Biomedical Engineering, University of California, Davis 95616, USA
| | | | | |
Collapse
|
34
|
Zhao S, Borden M, Bloch SH, Kruse D, Ferrara KW, Dayton PA. Radiation-Force Assisted Targeting Facilitates Ultrasonic Molecular Imaging. Mol Imaging 2004; 3:135-48. [PMID: 15530249 PMCID: PMC1356635 DOI: 10.1162/15353500200404115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Ultrasonic molecular imaging employs contrast agents, such as microbubbles, nanoparticles, or liposomes, coated with ligands specific for receptors expressed on cells at sites of angiogenesis, inflammation, or thrombus. Concentration of these highly echogenic contrast agents at a target site enhances the ultrasound signal received from that site, promoting ultrasonic detection and analysis of disease states. In this article, we show that acoustic radiation force can be used to displace targeted contrast agents to a vessel wall, greatly increasing the number of agents binding to available surface receptors. We provide a theoretical evaluation of the magnitude of acoustic radiation force and show that it is possible to displace micron-sized agents physiologically relevant distances. Following this, we show in a series of experiments that acoustic radiation force can enhance the binding of targeted agents: The number of biotinylated microbubbles adherent to a synthetic vessel coated with avidin increases as much as 20-fold when acoustic radiation force is applied; the adhesion of contrast agents targeted to alpha(v)beta3 expressed on human umbilical vein endothelial cells increases 27-fold within a mimetic vessel when radiation force is applied; and finally, the image signal-to-noise ratio in a phantom vessel increases up to 25 dB using a combination of radiation force and a targeted contrast agent, over use of a targeted contrast agent alone.
Collapse
|
35
|
Abstract
Targeted contrast agents are expanding the detectability and diagnosis of pathology from a strict anatomic to biochemical basis. Moreover, these new agents, in their various forms, offer the potential for site-specific drug and gene delivery, i.e., the "magic bullet" first postulated by Paul Erhlich 100 years ago. The ability to direct drugs to the molecular signatures of disease, to confirm noninvasively their presence at the site-of-interest, and to quantify the adequacy of local drug concentration at the time of treatment, ie, rational targeted drug delivery, offers exciting new clinical paradigms in the near future.
Collapse
|
36
|
Unger EC, Porter T, Culp W, Labell R, Matsunaga T, Zutshi R. Therapeutic applications of lipid-coated microbubbles. Adv Drug Deliv Rev 2004; 56:1291-314. [PMID: 15109770 DOI: 10.1016/j.addr.2003.12.006] [Citation(s) in RCA: 377] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2003] [Accepted: 12/20/2003] [Indexed: 11/15/2022]
Abstract
Lipid-coated microbubbles represent a new class of agents with both diagnostic and therapeutic applications. Microbubbles have low density. Stabilization of microbubbles by lipid coatings creates low-density particles with unusual properties for diagnostic imaging and drug delivery. Perfluorocarbon (PFC) gases entrapped within lipid coatings make microbubbles that are sufficiently stable for circulation in the vasculature as blood pool agents. Microbubbles can be cavitated with ultrasound energy for site-specific local delivery of bioactive materials and for treatment of vascular thrombosis. The blood-brain barrier (BBB) can be reversibly opened without damaging the neurons using ultrasound applied across the intact skull to cavitate microbubbles within the cerebral microvasculature for delivery of both low and high molecular weight therapeutic compounds to the brain. The first lipid-coated PFC microbubble product is currently marketed for diagnostic ultrasound imaging. Clinical trials are currently in process for treatment of vascular thrombosis with ultrasound and lipid-coated PFC microbubbles (SonoLysis Therapy). Targeted microbubbles and acoustically active PFC nanoemulsions with specific ligands can be developed for detecting disease at the molecular level and targeted drug and gene delivery. Bioactive compounds can be incorporated into these carriers for site-specific delivery. Our aim is to cover the therapeutic applications of lipid-coated microbubbles and PFC emulsions in this review.
Collapse
|
37
|
Abstract
Targeted ultrasound imaging uses acoustically active contrast agents bearing a ligand on the surface that binds to a function-specific molecule. These ultrasound contrast agents are typically gas-filled microbubbles, nongaseous liposomes, or lipid-encapsulated perfluorocarbon emulsions. Binding of the contrast agent to the target results in persistent contrast enhancement during ultrasound imaging. This approach has been applied to the ultrasound imaging of pathophysiologic processes such as inflammation associated with ischemia reperfusion, heart transplant rejection, atherosclerotic plaque, thrombus, and apoptosis.
Collapse
Affiliation(s)
- Flordeliza S Villanueva
- Division of Cardiology, Cardiovascular Institute, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA.
| | | | | | | |
Collapse
|
38
|
Takalkar AM, Klibanov AL, Rychak JJ, Lindner JR, Ley K. Binding and detachment dynamics of microbubbles targeted to P-selectin under controlled shear flow. J Control Release 2004; 96:473-82. [PMID: 15120903 DOI: 10.1016/j.jconrel.2004.03.002] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Accepted: 03/03/2004] [Indexed: 11/30/2022]
Abstract
This study was performed to assess the binding kinetics of a targeted microbubble contrast agent exposed to shear stress. An ultrasound contrast targeted to P-selectin was designed by conjugating monoclonal antibodies against murine P-selectin (RB40.34) to the lipid monolayer shell of the microbubble using poly(ethylene glycol)-biotin-streptavidin. The attachment and detachment of targeted microbubbles to P-selectin immobilized on a culture dish were assessed in a parallel-plate flow chamber. Targeted microbubbles (5 x 10(6) particles/ml) drawn through the flow chamber coated with P-selectin (109 sites/microm(2)) at a shear stress of 0.3 dyn/cm(2) accumulated at a rate of 565 mm(-2) min(-1). Attachment rates increased at higher plate surface densities of P-selectin, and microbubble detachment was reduced. Accumulation rate first increased with shear stress, reached a maximum at approximately 0.6 dyn/cm(2) and then decreased. Control experiments on a plate that lacked P-selectin, or was blocked with mAb RB40.34, resulted in minimal bubble attachment. Microbubble detachment was tested by ramping up shear stress at 30-s intervals. Half-maximal detachment was reached at 34 dyn/cm(2). Overall, accumulation and retention of targeted ultrasound contrast agents is possible under physiologic flow conditions and is strongly influenced by shear stress and surface density of the target receptor.
Collapse
Affiliation(s)
- Amol M Takalkar
- Cardiovascular Research Center and Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, VA 22908-1394, USA
| | | | | | | | | |
Collapse
|
39
|
Abstract
Molecular imaging is a rapidly evolving discipline with the goal of developing tools to display and quantify molecular and cellular targets in vivo. The heart of this field is based on the rational design and screening of targeted and activatable imaging reporter agents to sense fundamental processes of biology. Parallel advances in small animal imaging systems and in agent synthesis have allowed molecular imaging applications to extend into the in vivo arena. These advances have permitted, for example, in vivo sensing of inflammation, apoptosis, cell trafficking, and gene expression. In this review, we first review core principles of molecular imaging with an emphasis on smart, activatable agent technology. We then discuss applications of state-of-the-art molecular probes to interrogate important aspects of cardiovascular biology, with a focus on atherosclerosis, thrombosis, and heart failure. In the ensuing years, we anticipate that fundamental aspects of cardiovascular biology will be detectable in vivo, and that promising molecular imaging agents will be translated into the clinical arena to guide diagnosis and therapy of human cardiovascular illness.
Collapse
Affiliation(s)
- Farouc A Jaffer
- Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Charlestown, Mass 02129, USA.
| | | |
Collapse
|
40
|
Klibanov AL, Rasche PT, Hughes MS, Wojdyla JK, Galen KP, Wible JH, Brandenburger GH. Detection of Individual Microbubbles of Ultrasound Contrast Agents. Invest Radiol 2004; 39:187-95. [PMID: 15076011 DOI: 10.1097/01.rli.0000115926.96796.75] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES During echo examinations with microbubble contrast, individual "dots" of ultrasound reflection can be visualized. To address the question whether these signals represent individual microbubbles, very dilute suspensions of ultrasound contrast agents or individual microbubbles attached to Petri dishes were prepared and studied by ultrasound imaging. METHODS Microbubble suspensions were diluted in saline and evaluated by a clinical ultrasound imaging system. Microbubble concentration was verified by Coulter counter. Single microbubble preparation on a Petri dish was established by streptavidin-biotin interaction under microscopy control and subjected to ultrasound imaging. RESULTS Ultrasound of dilute microbubble dispersions demonstrated distinct white foci; concentration of these sites was consistent with signals from individual microbubbles as determined by Coulter. Individual microbubbles immobilized on polystyrene were also visualized by ultrasound. CONCLUSION Ultrasound medical systems can resolve backscatter signals from individual microbubbles of ultrasound contrast, both in solution and in the targeted immobilized state, implying picogram sensitivity.
Collapse
Affiliation(s)
- Alexander L Klibanov
- University of Virginia Cardiovascular Division, Cardiovascular Imaging Center, Charlottesville, Virginia 22908-0158, USA.
| | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
Ultrasound has received less attention than other imaging modalities for molecular imaging, but has a number of potential advantages. It is cheap, widely available and portable. Using Doppler methods, flow information can be obtained easily and non-invasively. It is arguably the most physiological modality, able to image structure and function with less sedation than other modalities. This means that function is minimally disturbed, and multiple repeat studies or the effect of interventions can easily be assessed. High frame rates of over 200 frames a second are achievable on current commercial systems, allowing for convenient cardiac studies in small animals. It can be used to guide interventional or invasive studies, such as needle placement. Ultrasound is also unique in being both an imaging and therapeutic tool and its value in gene therapy has received much recent interest. Ultrasound biomicroscopy has been used for in utero imaging and can guide injection of virus and cells. Ultrahigh frequency ultrasound can be used to determine cell mechanical properties. The development of microbubble contrast agents has opened many new opportunities, including new functional imaging methods, the ability to image capillary flow and the possibility of molecular targeting using labelled microbubbles.
Collapse
Affiliation(s)
- H-D Liang
- Ultrasound Group, Imaging Sciences Department, Imperial College London, Clinical Sciences Centre, Hammersmith Campus, Du Cane Road, London W12 0HS, UK
| | | |
Collapse
|
42
|
Abstract
The recent emergence of "molecular imaging" as an academic discipline has set the stage for an evolutionary leap in diagnostic imaging. Recent advances in nuclear, ultrasound, optical, and magnetic resonance imaging have generated interest in molecular imaging across all modalities and across various academic, industrial, and governmental agencies. In this perspective, examples of the progress and the prospects for the future of molecular imaging and linked targeted therapeutics are reviewed.
Collapse
Affiliation(s)
- Samuel A Wickline
- Department of Medicine, Barnes-Jewish Hospital and Washington University, St. Louis, MO, USA.
| | | |
Collapse
|
43
|
|
44
|
Eryol NK, Topsakal R, Kiranatli B, Abaci A, Ciçek Y, Oguzhan A, Başar E, Ergin A, Cetin S. Color Doppler tissue imaging to evaluate left atrial appendage function in mitral stenosis. Echocardiography 2003; 20:29-35. [PMID: 12848695 DOI: 10.1046/j.1540-8175.2003.00004.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Two-dimensional color Doppler tissue imaging (CDTI) has so far been used, in general, to evaluate ventricular function. This study examined if the left atrial appendage tissue velocity could reproducibly be measured with CDTI and if they have any predictive value for left atrial appendage (LAA) function and former thromboembolism. Thirty-six patients (24 women, 12 men; mean age 45 +/- 12 years; 18 AF; 11 former thromboembolic stroke) with mitral stenosis undergoing transesophageal echocardiography were examined with CDTI. Peak systolic tissue velocity (m/sec, peak systolic velocity [PSV]) was measured at the tip of the LAA in the basal short-axis view. LAA flow emptying (LAAEV) and filling (LAAFV) velocities (m/sec) were also recorded 1 cm immediately below the orifice of the appendage. Interobserver and intraobserver variabilities were determined for the PSV. LAA ejection fraction was measured by Simpson's method. Mitral regurgitation, AF, transmitral mean gradient, left ventricular ejection fraction, mitral valve area, and left atrial diameter were used as a covariant for adjustment. The intraobserver and interobserver correlation coefficients for the PSV using CDTI was 0.64 and 0.60, respectively (bothP = 0.01). LAAEV(0.29 +/- 0.09 vs 0.19 +/- 0.04, P = 0.001)and LAA ejection fraction(44 +/- 12 vs 29 +/- 14, P = 0.004)were found to be significantly decreased in the patients with decreased PSV (<0.05 m/sec), even after adjustment. The decreased PSV was positively correlated with the low LAAEV (<0.25 m/sec) and history of thromboembolism (r = 0.59, r = 0.38, respectively), and remained a significant determinant of the low LAAEV (OR 50.03, CI 1.46-1738.11,P = 0.02), but not of history of thromboembolism (OR 4.29, CI 0.52-35.01,P = 0.08) after adjustment. In conclusion, these results suggest that CDTI provides a reproducible method for quantification of contraction at the tip of the LAA. Decreased PSV may be predictive of poor LAA function.
Collapse
Affiliation(s)
- Namik Kemal Eryol
- Erciyes University of Medical School, Department of Cardiology, Kayseri, Turkey.
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Schumann PA, Christiansen JP, Quigley RM, McCreery TP, Sweitzer RH, Unger EC, Lindner JR, Matsunaga TO. Targeted-microbubble binding selectively to GPIIb IIIa receptors of platelet thrombi. Invest Radiol 2002; 37:587-93. [PMID: 12393970 DOI: 10.1097/00004424-200211000-00001] [Citation(s) in RCA: 178] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES New targeted microbubbles directed to the GPIIb IIIa receptor have been developed. The objective was to determine whether targeting microbubbles to clots would enhance ultrasound imaging. Systematic studies were designed to determine whether in vitro methodology is an acceptable predictor of in vivo efficacy. MATERIALS AND METHODS Bioconjugate ligands were inserted into lipid-coated membranes of perfluorocarbon gas microbubbles and binding studies performed on activated platelets immobilized on cell culture plates. Targeted microbubble binding to clots in a flow through chamber was also assessed. Finally, microbubble binding studies on arteriolar and venular clots in a mouse cremasteric muscle model were conducted. RESULTS Binding studies on platelet-immobilized plates demonstrated an affinity for targeted microbubbles versus untargeted microbubbles. Semiquantitative light obscuration techniques helped to measure extent of targeted microbubble binding. Targeted microbubbles similarly bound to platelet clots in the flow model. Finally, studies in the mouse model confirmed binding of targeted microbubbles in both venules and arterioles. CONCLUSION The use of receptor selective targeted microbubbles improved binding to vascular thrombi in both in vitro and in vivo settings.
Collapse
|
46
|
Abstract
The discipline of medical imaging is expanding to include both traditional anatomic modalities and new techniques for the functional assessment of the presence and extent of disease. Current FDA-approved ultrasound contrast agents are micron-sized bubbles with a stabilizing shell. Microbubble contrast agents can be used to estimate microvascular flow rate in a manner similar to dynamic contrast-enhanced magnetic resonance imaging (MRI). The concentration of these agents within the vasculature, reticulo-endothelial, or lymphatic systems produces an effective passive targeting of these areas. Liquid-filled nanoparticles and liposomes have also demonstrated echogenicity and are under evaluation as ultrasound contrast agents. Actively targeted ultrasound relies on specially designed contrast agents to localize the targeted molecular signature or physiologic system. These agents typically remain within the vascular space, and therefore possible targets include molecular markers on thrombus, endothelial cells, and leukocytes. The purpose of this review is to summarize the requirements, challenges, current progress, and future directions of targeted imaging with ultrasound.
Collapse
Affiliation(s)
- Paul A Dayton
- Department of Biomedical Engineering, University of California-Davis, Davis, California 95616, USA
| | | |
Collapse
|
47
|
Tardy I, Pochon S, Theraulaz M, Nanjappan P, Schneider M. In vivo ultrasound imaging of thrombi using a target-specific contrast agent. Acad Radiol 2002; 9 Suppl 2:S294-6. [PMID: 12188252 DOI: 10.1016/s1076-6332(03)80207-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- I Tardy
- Bracco Research SA, Geneva, Switzerland
| | | | | | | | | |
Collapse
|
48
|
Unger EC, Matsunaga TO, McCreery T, Schumann P, Sweitzer R, Quigley R. Therapeutic applications of microbubbles. Eur J Radiol 2002; 42:160-8. [PMID: 11976013 DOI: 10.1016/s0720-048x(01)00455-7] [Citation(s) in RCA: 226] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Microbubbles, currently used as contrast agents have potential therapeutic applications. Microbubbles, upon insonation of sufficiently intense ultrasound will cavitate. Cavitation with microbubbles can be used to dissolve blood clots or deliver drugs. Targeting ligands and drugs can be incorporated into microbubbles to make highly specific diagnostic and therapeutic agents for activation with ultrasound. In this paper I will review some of these potential applications and experimental results using such agents for thrombolysis, drug and gene delivery.
Collapse
Affiliation(s)
- Evan C Unger
- ImaRx Therapeutics, Inc., 1635 East 18th St., Tucson, AZ 85719, USA
| | | | | | | | | | | |
Collapse
|
49
|
|
50
|
Abstract
Targeted contrast agents are expanding the detectability and diagnosis of pathology from a strict anatomic to biochemical basis. Moreover, these new agents, in their various forms, offer the potential for site-specific drug and gene delivery, ie, the "magic bullet" first postulated by Paul Erhlich 100 years ago. The ability to direct drugs to the molecular signatures of disease, to confirm noninvasively their presence at the site-of-interest, and to quantify the adequacy of local drug concentration at the time of treatment, ie, rational targeted drug delivery, offers exciting new clinical paradigms in the near future.
Collapse
Affiliation(s)
- G M Lanza
- Division of Cardiology, Washington University Medical School, St Louis, MO 63110, USA
| | | |
Collapse
|