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MRI of vulnerable plaque. CURRENT CARDIOVASCULAR IMAGING REPORTS 2009. [DOI: 10.1007/s12410-009-0002-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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52
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Barry SE. Challenges in the development of magnetic particles for therapeutic applications. Int J Hyperthermia 2009; 24:451-66. [PMID: 18608583 DOI: 10.1080/02656730802093679] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Certain iron-based particle formulations have useful magnetic properties that, when combined with low toxicity and desirable pharmacokinetics, encourage their development for therapeutic applications. This mini-review begins with background information on magnetic particle use as MRI contrast agents and the influence of material size on pharmacokinetics and tissue penetration. Therapeutic investigations, including (1) the loading of bioactive materials, (2) the use of stationary, high-gradient (HG) magnetic fields to concentrate magnetic particles in tissues or to separate material bound to the particles from the body, and (3) the application of high power alternating magnetic fields (AMF) to generate heat in magnetic particles for hyperthermic therapeutic applications are then surveyed. Attention is directed mainly to cancer treatment, as selective distribution to tumors is well-suited to particulate approaches and has been a focus of most development efforts. While magnetic particles have been explored for several decades, their use in therapeutic products remains minimal; a discussion of future directions and potential ways to better leverage magnetic properties and to integrate their use into therapeutic regimens is discussed.
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Affiliation(s)
- Stephen E Barry
- Alnis BioSciences, Inc., Research Triangle Park, NC 27709, USA.
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53
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Beckmann N, Cannet C, Babin AL, Blé F, Zurbruegg S, Kneuer R, Dousset V. In vivo
visualization of macrophage infiltration and activity in inflammation using magnetic resonance imaging. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2009; 1:272-98. [DOI: 10.1002/wnan.16] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Nicolau Beckmann
- Global Imaging Group, Novartis Institutes for BioMedical Research, CH‐4056 Basel, Switzerland
| | - Catherine Cannet
- Global Imaging Group, Novartis Institutes for BioMedical Research, CH‐4056 Basel, Switzerland
| | - Anna Louise Babin
- Global Imaging Group, Novartis Institutes for BioMedical Research, CH‐4056 Basel, Switzerland
- Respiratory Diseases Department, Novartis Institutes for BioMedical Research, CH‐4056 Basel, Switzerland
- Sackler Institute of Pulmonary Pharmacology, King's College, London SE1 1UL, UK
| | - François‐Xavier Blé
- Respiratory Diseases Department, Novartis Institutes for BioMedical Research, CH‐4056 Basel, Switzerland
- Mouse Imaging Centre, Toronto Centre for Phenogenomics, Toronto, Canada M5T 3H7
| | - Stefan Zurbruegg
- Global Imaging Group, Novartis Institutes for BioMedical Research, CH‐4056 Basel, Switzerland
| | - Rainer Kneuer
- Global Imaging Group, Novartis Institutes for BioMedical Research, CH‐4056 Basel, Switzerland
| | - Vincent Dousset
- University Victor Segalen Bordeaux 2, EA 2966 Neurobiology of Myelin Disease Laboratory, CHU de Bordeaux, F‐33076 Bordeaux, France
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54
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Uchida M, Terashima M, Cunningham CH, Suzuki Y, Willits DA, Willis AF, Yang PC, Tsao PS, McConnell MV, Young MJ, Douglas T. A human ferritin iron oxide nano-composite magnetic resonance contrast agent. Magn Reson Med 2008; 60:1073-81. [DOI: 10.1002/mrm.21761] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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55
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Korosoglou G, Weiss RG, Kedziorek DA, Walczak P, Gilson WD, Schär M, Sosnovik DE, Kraitchman DL, Boston RC, Bulte JWM, Weissleder R, Stuber M. Noninvasive detection of macrophage-rich atherosclerotic plaque in hyperlipidemic rabbits using "positive contrast" magnetic resonance imaging. J Am Coll Cardiol 2008; 52:483-91. [PMID: 18672170 DOI: 10.1016/j.jacc.2008.03.063] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 02/12/2008] [Accepted: 03/19/2008] [Indexed: 11/16/2022]
Abstract
OBJECTIVES This study was designed to identify macrophage-rich atherosclerotic plaque noninvasively by imaging the tissue uptake of long-circulating superparamagnetic nanoparticles with a positive contrast off-resonance imaging sequence (inversion recovery with ON-resonant water suppression [IRON]). BACKGROUND The sudden rupture of macrophage-rich atherosclerotic plaques can trigger the formation of an occlusive thrombus in coronary vessels, resulting in acute myocardial infarction. Therefore, a noninvasive technique that can identify macrophage-rich plaques and thereby assist with risk stratification of patients with atherosclerosis would be of great potential clinical utility. METHODS Experiments were conducted on a clinical 3-T magnetic resonance imaging (MRI) scanner in 7 heritable hyperlipidemic and 4 control rabbits. Monocrystalline iron-oxide nanoparticles (MION)-47 were administrated intravenously (2 doses of 250 mumol Fe/kg), and animals underwent serial IRON-MRI before injection of the nanoparticles and serially after 1, 3, and 6 days. RESULTS After administration of MION-47, a striking signal enhancement was found in areas of plaque only in hyperlipidemic rabbits. The magnitude of enhancement on magnetic resonance images had a high correlation with the number of macrophages determined by histology (p < 0.001) and allowed for the detection of macrophage-rich plaque with high accuracy (area under the curve: 0.92, SE: 0.04, 95% confidence interval: 0.84 to 0.96, p < 0.001). No significant signal enhancement was measured in remote areas without plaque by histology and in control rabbits without atherosclerosis. CONCLUSIONS Using IRON-MRI in conjunction with superparamagnetic nanoparticles is a promising approach for the noninvasive evaluation of macrophage-rich, vulnerable plaques.
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56
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Morris JB, Olzinski AR, Jucker BM. Patterns of USPIO Deposition in Murine Atherosclerosis. Arterioscler Thromb Vasc Biol 2008. [DOI: 10.1161/atvbaha.108.170704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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57
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Briley-Saebo KC, Mani V, Hyafil F, Cornily JC, Fayad ZA. Fractionated Feridex and positive contrast: in vivo MR imaging of atherosclerosis. Magn Reson Med 2008; 59:721-30. [PMID: 18383304 DOI: 10.1002/mrm.21541] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Macrophages have been identified as a critical factor in the pathogenesis of atherosclerosis. Ultrasmall iron oxide particles (USPIOs) have been used to passively target intraplaque macrophages. For dextran-based USPIOs, uptake into macrophages may be modulated by particle size. The aim of the current study was to test the efficacy of fractionated Feridex with respect to macrophage uptake in atherosclerotic rabbits. Fractionation of Feridex resulted in a 15-nm USPIO that exhibited a blood half-life of 15.9 h and liver retention of 6.4%. Blood clearance and liver retention of Feridex was 0.46 h and 60%, following administration of 4.8 mg Fe/kg Feridex. Atherosclerotic rabbits were administered 0.5 or 4.8 mg Fe/kg dosages of either fractionated Feridex or Feridex. MRI was performed at 1.5T over a 24-h time period postinjection. Perls and RAM-11 staining was performed to identify iron deposition. MRI showed a dose-dependent signal loss using conventional gradient echo (GRE) sequences following administration of fractionated Feridex. Even at low dose, significant signal loss was observed that correlated with histology. No signal attenuation or iron deposition was observed in the vessel wall of rabbits administered Feridex. Results of this study suggest that it may be possible to optimize USPIOs for intraplaque macrophage detection.
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Affiliation(s)
- Karen C Briley-Saebo
- Department of Radiology, Mount Sinai School of Medicine, New York, New York 10029-6574, USA.
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58
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Jarrett BR, Gustafsson B, Kukis DL, Louie AY. Synthesis of 64Cu-labeled magnetic nanoparticles for multimodal imaging. Bioconjug Chem 2008; 19:1496-504. [PMID: 18578485 DOI: 10.1021/bc800108v] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Complementary imaging modalities provide more information than either method alone can yield and we have developed a dual-mode imaging probe for combined magnetic resonance (MR) and positron emission tomography (PET) imaging. We have developed dual-mode PET/MRI active probes targeted to vascular inflammation and present synthesis of (1) an aliphatic amine polystyrene bead and (2) a novel superparamagnetic iron oxide nanoparticle targeted to macrophages that were both coupled to positron-emitting copper-64 isotopes. The amine groups of the polystyrene beads were directly conjugated with an amine-reactive form (isothiocyanate) of aza-macrocycle 1,4,7,10-tetraazacyclo-dodecane-1,4,7,10-tetraacetic acid (DOTA). Iron oxide nanoparticles are dextran sulfate coated, and the surface was modified to contain aldehyde groups to conjugate to an amine-activated DOTA. Incorporation of chelated Cu-64 to nanoparticles under these conditions, which is routinely used to couple DOTA to macromolecules, was unexpectedly difficult and illustrates that traditional conjugation methods do not always work in a nanoparticle environment. Therefore, we developed new methods to couple Cu-64 to nanoparticles and demonstrate successful labeling to a range of nanoparticle types. We obtained labeling yields of 24% for the amine polystyrene beads and 21% radiolabeling yield for the anionic dextran sulfate iron oxide nanoparticles. The new coupling chemistry can be generalized for attaching chelated metals to other nanoparticle platforms.
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Affiliation(s)
- Benjamin R Jarrett
- Department of Biomedical Engineering, University of California-Davis, Davis, California 95616, USA
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59
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Morris JB, Olzinski AR, Bernard RE, Aravindhan K, Mirabile RC, Boyce R, Willette RN, Jucker BM. p38 MAPK inhibition reduces aortic ultrasmall superparamagnetic iron oxide uptake in a mouse model of atherosclerosis: MRI assessment. Arterioscler Thromb Vasc Biol 2007; 28:265-71. [PMID: 18162612 DOI: 10.1161/atvbaha.107.151175] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Ultrasmall superparamagnetic iron oxide (USPIO) contrast agents have been used for noninvasive MRI assessment of atherosclerotic plaque inflammation. The purpose of this study was to noninvasively evaluate USPIO uptake in aorta of apoE-/- mice and to determine the effects of Angiotensin II (Ang II) infusion and chronic antiinflammatory treatment with a p38 MAPK inhibitor on this uptake. METHODS AND RESULTS ApoE-/- mice were administered saline or Ang II (1.44 mg/kg/d) for 21 days. In vivo MRI assessment of USPIO uptake in the aortic arch was observed in all animals. However, although the Ang II group had significantly higher absolute iron content (increased 103%, P<0.001) in the aortic arch compared with the saline group, the p38 MAPK inhibitor (SB-239063, 150 mg/kg/d) treatment group did not (increased 6%, NS). The in vivo MRI signal intensity was significantly correlated to the absolute iron content in the aortic arch. Histological evaluation of the aortic root lesion area showed colocalization of USPIO with macrophages and a reduction in USPIO but not macrophage content with SB-239063 treatment. CONCLUSIONS The present study demonstrates that noninvasive assessment of USPIO uptake, as a marker for inflammation in murine atherosclerotic plaque, is feasible and that p38 MAPK inhibition attenuates the uptake of USPIO in aorta of Ang II-infused apoE-/- mice.
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Affiliation(s)
- Joanne B Morris
- GlaxoSmithKline, 709 Swedeland Rd, King of Prussia, PA 19406, USA
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60
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Wu YJ, Muldoon LL, Varallyay C, Markwardt S, Jones RE, Neuwelt EA. In vivo leukocyte labeling with intravenous ferumoxides/protamine sulfate complex and in vitro characterization for cellular magnetic resonance imaging. Am J Physiol Cell Physiol 2007; 293:C1698-708. [PMID: 17898131 DOI: 10.1152/ajpcell.00215.2007] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cellular labeling with ferumoxides (Feridex IV) superparamagnetic iron oxide nanoparticles can be used to monitor cells in vivo by MRI. The objective of this study was to use histology and MRI to evaluate an in vivo, as opposed to in vitro, technique for labeling of mononuclear leukocytes as a means of tracking inflammatory processes in the brain. Long-Evans rats were intravenously injected with 20 mg/kg ferumoxides, ferumoxtran-10, or ferumoxytol with or without protamine sulfate. Leukocytes and splenocytes were evaluated by cell sorting and iron histochemistry or were implanted into the brain for MRI. Injection of ferumoxides/protamine sulfate complex IV resulted in iron labeling of leukocytes (ranging from 7.4 ± 0.5% to 12.5 ± 0.9% with average 9.2 ± 0.8%) compared with ferumoxides (ranging from 3.9 ± 0.4% to 6.3 ± 0.5% with average 5.0 ± 0.5%) or protamine sulfate alone (ranging from 0% to 0.9 ± 0.7% with average 0.3 ± 0.3%). Cell sorting analysis indicated that iron-labeled cells were enriched for cell types positive for the myelomonocytic marker (CD11b/c) and the B lymphocyte marker (CD45RA) and depleted in the T cell marker (CD3). Neither ferumoxtran-10 nor ferumoxytol with protamine sulfate labeled leukocytes. In vivo ferumoxides/protamine sulfate-loaded leukocytes and splenocytes were detected by MRI after intracerebral injection. Ferumoxides/protamine complex labeled CD45RA-positive and CD11b/c-positive leukocytes in vivo without immediate toxicity. The dose of feumoxides in this report is much higher than the approved human dose, so additional animal studies are required before this approach could be translated to the clinic. These results might provide useful information for monitoring leukocyte trafficking into the brain.
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Affiliation(s)
- Y Jeffrey Wu
- Research Service, Veterans Administration Medical Center, Oregon Health and Sciences University, Portland, Oregon 97239, USA
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61
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Sigovan M, Boussel L, Sulaiman A, Sappey-Marinier D, Desbleds-Mansard C, Ibarrola D, Gamondes D, Corot C, Lancelot E, Raynaud JS, Violas X, Douek P, Canet-Soulas E. CMR 2007: 1.04:In-vivo USPIO's follow-up and optimized MRI protocol for inflammation imaging in atherosclerotic plaques. CONTRAST MEDIA & MOLECULAR IMAGING 2007. [DOI: 10.1002/cmmi.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Canet-Soulas E, Letourneur D. Biomarkers of atherosclerosis and the potential of MRI for the diagnosis of vulnerable plaque. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2007; 20:129-42. [PMID: 17605060 DOI: 10.1007/s10334-007-0078-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Accepted: 06/04/2007] [Indexed: 12/20/2022]
Abstract
Atherosclerosis is a chronic inflammatory vascular disease. As it is an inflammation process, many cellular and molecular events are involved at each step of the progression of atherosclerosis from an early fatty streak lesion to a highly dangerous rupture-prone plaque. Magnetic resonance imaging (MRI) is a well-established diagnostic tool for many kinds of chronic inflammation in various systems and organs, and recent improvements in spatial resolution and contrast strategies make it a promising technique for the characterization of inflammatory vessel walls. The first part of this review will briefly introduce the main cellular and molecular processes involved in atherosclerotic lesions; the second part will focus on the use of high-resolution MRI and present-generation contrast agents for plaque characterization; and the third part will present some recent and ongoing cellular and molecular MRI studies of atherosclerosis.
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Affiliation(s)
- E Canet-Soulas
- Université Lyon 1, ESCPE, Laboratoire CREATIS-LRMN, CNRS UMR 5220, INSERM U630, Domaine Scientifique de la Doua, 43 Bd 11 novembre 1918, 69622 Villeurbanne Cedex, France.
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63
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Briley-Saebo KC, Amirbekian V, Mani V, Aguinaldo JGS, Vucic E, Carpenter D, Amirbekian S, Fayad ZA. Gadolinium mixed-micelles: effect of the amphiphile on in vitro and in vivo efficacy in apolipoprotein E knockout mouse models of atherosclerosis. Magn Reson Med 2007; 56:1336-46. [PMID: 17089381 DOI: 10.1002/mrm.21094] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Gadolinium (Gd) micelles are nanoparticles that incorporate phospholipids, surfactants, and lipophilic Gd complexes. Preliminary studies have shown that lipid-based nanoparticles may penetrate atherosclerotic plaque. The aim of the current study was to prepare, characterize, and evaluate in vivo the efficacy of two Gd micelle formulations using apolipoprotein E knockout (ApoE(-/-)) mouse models of atherosclerosis. Gd micelles were prepared using two different amphiphiles but similar GdDTPA lipids, surfactants, and fluorescent labels. The results indicate that the choice of amphiphile may affect the particle size, relaxivity, and blood clearance in wild-type mice (WT). However, the in vivo MR efficacy, with respect to uptake in the vessel wall of ApoE(-/-) mice, was not affected by the amphiphile used. Significant wall enhancement of ApoE(-/-) mice was observed following administration of 0.015 and 0.038 mmol Gd/kg of both micelle formulations. No significant enhancement of the vessel wall of WT mice was observed for any of the dosages or formulations tested. Additionally, liver uptake 24 hr post-injection (p.i.) was not influenced by the choice of amphiphile. The results of this study strongly suggest that liver uptake and wall enhancement may be regulated by the surface properties of the micelle and not by other factors, such as micelle size.
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Affiliation(s)
- Karen C Briley-Saebo
- Imaging Science Laboratories, Department of Radiology, Mount Sinai School of Medicine, New York, New York 10029-6574, USA
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64
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Jarrett BR, Frendo M, Vogan J, Louie AY. Size-controlled synthesis of dextran sulfate coated iron oxide nanoparticles for magnetic resonance imaging. NANOTECHNOLOGY 2007; 18:035603. [PMID: 19636126 DOI: 10.1088/0957-4484/18/3/035603] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In the generation of nanoparticles for biological applications, the control over synthetic parameters influencing the particles' physicochemical properties are of great interest due to the strong influence of particle size and surface properties on cellular uptake and biodistribution. We have synthesized dextran sulfate coated particles and systematically evaluated synthetic parameters that may influence the properties of these nanoparticles as potential magnetic resonance (MR) contrast agents. The amount of base, polysaccharide content, ratio of iron salts, and reaction time were optimized to yield approximately 30 nm particles as determined by dynamic light scattering with good MR properties (r(1) = 14.46 mM(-1) s(-1) and r(2) = 72.55 mM(-1) s(-1)) and in good yield (50%). Particle sizes and relaxivities are compared with clinically available dextran coated particles and the resulting physical properties of the dextran sulfate coated particles show these particles could be used as potential MR contrast agents for cardiovascular imaging.
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Affiliation(s)
- Benjamin R Jarrett
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
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65
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Amirbekian V, Lipinski MJ, Briley-Saebo KC, Amirbekian S, Aguinaldo JGS, Weinreb DB, Vucic E, Frias JC, Hyafil F, Mani V, Fisher EA, Fayad ZA. Detecting and assessing macrophages in vivo to evaluate atherosclerosis noninvasively using molecular MRI. Proc Natl Acad Sci U S A 2007; 104:961-6. [PMID: 17215360 PMCID: PMC1766334 DOI: 10.1073/pnas.0606281104] [Citation(s) in RCA: 316] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Indexed: 11/18/2022] Open
Abstract
We investigated the ability of targeted immunomicelles to detect and assess macrophages in atherosclerotic plaque using MRI in vivo. There is a large clinical need for a noninvasive tool to assess atherosclerosis from a molecular and cellular standpoint. Macrophages play a central role in atherosclerosis and are associated with plaques vulnerable to rupture. Therefore, macrophage scavenger receptor (MSR) was chosen as a target for molecular MRI. MSR-targeted immunomicelles, micelles, and gadolinium-diethyltriaminepentaacetic acid (DTPA) were tested in ApoE-/- and WT mice by using in vivo MRI. Confocal laser-scanning microscopy colocalization, macrophage immunostaining and MRI correlation, competitive inhibition, and various other analyses were performed. In vivo MRI revealed that at 24 h postinjection, immunomicelles provided a 79% increase in signal intensity of atherosclerotic aortas in ApoE-/- mice compared with only 34% using untargeted micelles and no enhancement using gadolinium-DTPA. Confocal laser-scanning microscopy revealed colocalization between fluorescent immunomicelles and macrophages in plaques. There was a strong correlation between macrophage content in atherosclerotic plaques and the matched in vivo MRI results as measured by the percent normalized enhancement ratio. Monoclonal antibodies to MSR were able to significantly hinder immunomicelles from providing contrast enhancement of atherosclerotic vessels in vivo. Immunomicelles provided excellent validated in vivo enhancement of atherosclerotic plaques. The enhancement seen is related to the macrophage content of the atherosclerotic vessel areas imaged. Immunomicelles may aid in the detection of high macrophage content associated with plaques vulnerable to rupture.
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Affiliation(s)
- Vardan Amirbekian
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
- Johns Hopkins University School of Medicine, Baltimore, MD 21205
- The Sarnoff Cardiovascular Research Foundation, Great Falls, VA 22066
| | - Michael J. Lipinski
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
- The Sarnoff Cardiovascular Research Foundation, Great Falls, VA 22066
| | - Karen C. Briley-Saebo
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Smbat Amirbekian
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
- Emory University School of Medicine, Atlanta, GA 30322; and
| | - Juan Gilberto S. Aguinaldo
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - David B. Weinreb
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Esad Vucic
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Juan C. Frias
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Fabien Hyafil
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | - Venkatesh Mani
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
| | | | - Zahi A. Fayad
- *The Imaging Science Laboratories, Department of Radiology, the Zena and Michael A. Wiener Cardiovascular Institute, the Marie-Josée and Henry R. Kravis Cardiovascular Health Center, and Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029
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Durand E, Raynaud JS, Bruneval P, Brigger I, Al Haj Zen A, Mandet C, Lancelot E, Lafont A. Magnetic resonance imaging of ruptured plaques in the rabbit with ultrasmall superparamagnetic particles of iron oxide. J Vasc Res 2007; 44:119-28. [PMID: 17215583 DOI: 10.1159/000098484] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Accepted: 10/22/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Magnetic resonance imaging (MRI) enhanced with ultrasmall superparamagnetic particles of iron oxide (USPIO) has previously been evaluated in hyperlipidemic rabbits. The aim of this study was therefore to compare USPIO in ruptured and non-ruptured arteries in an atherosclerotic rabbit model. METHODS Atherosclerotic-like lesions were induced by the combination of endothelial abrasion and high-cholesterol diet in iliac rabbit arteries (n = 16). Rupture of atherosclerotic lesions was realized by oversized balloon angioplasty in one iliac artery, whereas the contralateral artery was used as control. USPIO (ferumoxtran-10: 1 mmol Fe/kg) was administered immediately (n = 10) or 28 days (n = 6) after injury. MRI and histological analysis were performed 7 and 35 days after injury and in control arteries. RESULTS In vivo MRI analysis showed extended susceptibility artifact with transluminal signal loss in all ruptured arteries 7 days after injury. In contrast, hyposignal was reduced 35 days following injury (i.e. after healing), and absent in non-ruptured arteries. Similarly, histological analysis of iron uptake was significantly increased 7 days after injury compared to healed-ruptured and control arteries. CONCLUSIONS Accumulation ofUSPIO is significantly increased in ruptured as compared to non-ruptured arteries in the atherosclerotic rabbit model.
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Affiliation(s)
- E Durand
- Service de Cardiologie, Ap-HP, HEGP, Unité INSERM E00-16, Faculté de Médecine, Université Paris-Descartes, Paris, France.
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Woo DC, Kim BS, Jung SL, Park HJ, Rhim HS, Jahng GH, Choe BY. Development of a cone-shape phantom for multi-voxel MR spectroscopy. J Neurosci Methods 2007; 162:101-7. [PMID: 17292479 DOI: 10.1016/j.jneumeth.2006.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 11/23/2006] [Accepted: 12/17/2006] [Indexed: 10/23/2022]
Abstract
The purpose of this study was to develop a cone-shape phantom for multi-voxel magnetic resonance spectroscopy (MRS) and to evaluate MR spectra using the cone-shape phantom we developed in this study. A cone-shape MRS phantom was developed with a combination of cone-shape vials. The cylindrical main body was made of acrylic resin and the cone-shape vials were fabricated from poly-ethylene cones. Each cone of the phantom was filled with various metabolite materials. 1.5T GE and 3T Philips systems were used for the single voxel spectroscopy (SVS) as well as for the multi-voxel spectroscopy (MVS). Identification and quantification of the metabolite materials in the cone-shape phantom were done by the SAGE post-program. The MR images and spectra of the cone-shape phantom were obtained from the assigned slice position. The high order shimming control provided enhanced resolution in the SVS and MVS. The area and amplitude were proportional to the metabolite volume in the voxel. The present study demonstrated that the cone-shape phantom was useful for the metabolite quantification. Thus, we propose that the cone-shape phantom can be used for the evaluation of quality control of the MR spectra obtained from SVS and MVS.
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Affiliation(s)
- Dong-Cheol Woo
- Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, #505 Banpo-Dong, Seocho-Gu, Seoul 137-040, South Korea
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68
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Briley-Saebo KC, Mulder WJM, Mani V, Hyafil F, Amirbekian V, Aguinaldo JGS, Fisher EA, Fayad ZA. Magnetic resonance imaging of vulnerable atherosclerotic plaques: Current imaging strategies and molecular imaging probes. J Magn Reson Imaging 2007; 26:460-79. [PMID: 17729343 DOI: 10.1002/jmri.20989] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The vulnerability or destabilization of atherosclerotic plaques has been directly linked to plaque composition. Imaging modalities, such as magnetic resonance (MR) imaging, that allow for evaluation of plaque composition at a cellular and molecular level, could further improve the detection of vulnerable plaque and may allow for monitoring the efficacy of antiatherosclerotic therapies. In this review we focus on MR imaging strategies for the detection and evaluation of atherosclerotic plaques and their composition. We highlight recent advancements in the development of MR pulse sequences, computer image analysis, and the use of commercially available MR contrast agents, such as gadopentic acid (Gd-DTPA), for plaque characterization. We also discuss molecular imaging strategies that are currently being used to design specific imaging probes targeted to biochemical and cellular markers of atherosclerotic plaque vulnerability.
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Affiliation(s)
- Karen C Briley-Saebo
- Imaging Science Laboratories, Department of Radiology, Mount Sinai School of Medicine, New York, New York, USA
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69
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Lipinski MJ, Amirbekian V, Frias JC, Aguinaldo JGS, Mani V, Briley-Saebo KC, Fuster V, Fallon JT, Fisher EA, Fayad ZA. MRI to detect atherosclerosis with gadolinium-containing immunomicelles targeting the macrophage scavenger receptor. Magn Reson Med 2006; 56:601-10. [PMID: 16902977 DOI: 10.1002/mrm.20995] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The ability to specifically image macrophages may enable improved detection and characterization of atherosclerosis. In this study we evaluated the in vitro uptake of gadolinium (Gd)-containing immunomicelles (micelles linked to macrophage-specific antibody), micelles, and standard contrast agents by murine macrophages, and sought to determine whether immunomicelles and micelles improve ex vivo imaging of apolipoprotein E knockout (ApoE KO) murine atherosclerosis. Murine RAW 264.7 macrophages were incubated with Gd-DTPA, micelles, and immunomicelles. Cell pellets were prepared and imaged using a 1.5 T MR system with an inversion recovery spin-echo sequence to determine the in vitro T1 values. Ex vivo analysis of mouse aortas was performed using a 9.4T MR system with a high-spatial-resolution sequence (78x39x78 microm3). The T1 value was significantly decreased in cells treated with micelles compared to Gd-DTPA (P<0.0001), and in cells incubated at 4 degrees C with immunomicelles compared to micelles (P<0.05). Ex vivo MRI signal intensity (SI) was significantly increased by 81% and 20% in aortas incubated with immunomicelles and micelles, respectively. Confocal microscopy demonstrated in vitro and ex vivo uptake of fluorescent immunomicelles by macrophages. Immunomicelles and micelles improve in vitro and ex vivo MR detection of macrophages, and may prove useful in the detection of macrophage-rich plaques.
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Affiliation(s)
- Michael J Lipinski
- Zena and Michael A. Wiener Cardiovascular Institute, Marie-Josée and Henry R. Kravis Cardiovascular Health Center, Imaging Science Laboratories, Department of Radiology, Mount Sinai School of Medicine, New York, New York 10029, USA
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70
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Uchida M, Flenniken ML, Allen M, Willits DA, Crowley BE, Brumfield S, Willis AF, Jackiw L, Jutila M, Young MJ, Douglas T. Targeting of Cancer Cells with Ferrimagnetic Ferritin Cage Nanoparticles. J Am Chem Soc 2006; 128:16626-33. [PMID: 17177411 DOI: 10.1021/ja0655690] [Citation(s) in RCA: 281] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein cage architectures such as virus capsids and ferritins are versatile nanoscale platforms amenable to both genetic and chemical modification. Incorporation of multiple functionalities within these nanometer-sized protein architectures demonstrate their potential to serve as functional nanomaterials with applications in medical imaging and therapy. In the present study, we synthesized an iron oxide (magnetite) nanoparticle within the interior cavity of a genetically engineered human H-chain ferritin (HFn). A cell-specific targeting peptide, RGD-4C which binds alphavbeta3 integrins upregulated on tumor vasculature, was genetically incorporated on the exterior surface of HFn. Both magnetite-containing and fluorescently labeled RGD4C-Fn cages bound C32 melanoma cells in vitro. Together these results demonstrate the capability of a genetically modified protein cage architecture to serve as a multifunctional nanoscale container for simultaneous iron oxide loading and cell-specific targeting.
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Affiliation(s)
- Masaki Uchida
- Department of Chemistry and Biochemistry, and Center for Bio-Inspired Nanomaterials (CBIN), Montana State University, Bozeman, MT 59717, USA
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71
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von Zur Muhlen C, von Elverfeldt D, Bassler N, Neudorfer I, Steitz B, Petri-Fink A, Hofmann H, Bode C, Peter K. Superparamagnetic iron oxide binding and uptake as imaged by magnetic resonance is mediated by the integrin receptor Mac-1 (CD11b/CD18): implications on imaging of atherosclerotic plaques. Atherosclerosis 2006; 193:102-11. [PMID: 16997307 DOI: 10.1016/j.atherosclerosis.2006.08.048] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Revised: 07/23/2006] [Accepted: 08/23/2006] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Superparamagnetic iron oxide nanoparticles (SPIONs) have been successfully used for magnetic resonance imaging (MRI) of atherosclerotic plaques. Endocytosis into monocytes/macrophages has been proposed as the mechanism for SPION uptake, but a specific receptor has not been identified yet. A potential candidate is the versatile integrin Mac-1 (CD11b/CD18, alphaMbeta2), which is involved in leukocyte adhesion, complement activation and phagocytosis. METHODS AND RESULTS Intracellular SPION-accumulation was confirmed in cultured human monocytes using immunohistochemistry and iron staining. Recombinant cells expressing Mac-1 in different activation states as well as human monocytes with or without PMA stimulation were incubated either with an unspecific IgG or a CD11b-blocking antibody. Thereafter, cells were incubated with FITC-labeled amino-covered SPIONs or ferumoxtran-10 SPIONs and signal intensity was quantified by flow cytometry. Depending on the activation status of Mac-1, a significant increase in SPION binding/uptake was observed, independent on surface coating. Furthermore, SPION binding/uptake was significantly reduced after CD11b blockade. Results were confirmed in recombinant cells incubated with amino-PVA SPIONs and ferumoxtran-10, using T2(*)-weighted 3T MRI. CONCLUSION The integrin Mac-1 is directly involved in SPION binding/uptake. Thus, monocytes abundantly expressing Mac-1 and especially activated monocytes expressing activated Mac-1 may be useful vehicles for high resolution MRI labeling of atherosclerotic plaques.
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Affiliation(s)
- C von Zur Muhlen
- Department of Cardiology & Angiology, University Hospital of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
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72
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Muldoon LL, Sàndor M, Pinkston KE, Neuwelt EA. Imaging, distribution, and toxicity of superparamagnetic iron oxide magnetic resonance nanoparticles in the rat brain and intracerebral tumor. Neurosurgery 2006; 57:785-96; discussion 785-96. [PMID: 16239893 DOI: 10.1093/neurosurgery/57.4.785] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE Superparamagnetic iron oxide nanoparticle magnetic resonance imaging (MRI) contrast agents are gaining use in the central nervous system. The purpose of this study was to evaluate the imaging characteristics, distribution, time course, and neurotoxicity of the clinical agents ferumoxtran-10, ferumoxides, and ferumoxytol, and the laboratory preparation MION-46 in rat brain. METHODS Iron oxide agents were administered by intracerebral inoculation or intraarterially after osmotic blood-brain barrier opening in normal rats and intravenously in nude rats with intracerebral tumor xenografts. Rat brains were imaged by MRI at multiple time points and then were assessed for iron histochemistry and pathological features. RESULTS After intracerebral injection, MRI signal changes declined slowly over weeks to months. After transvascular delivery, transient (3 d) enhancement was seen with ferumoxtran-10 or ferumoxytol, whereas ferumoxides induced long-term (28 d) signal dropout. No pathological brain cell or myelin changes were detected after delivery of the clinical iron oxide agents to normal brains. In tumor models, ferumoxtran-10 enhanced one small-cell lung carcinoma intracerebral tumor, which correlated with iron staining in cells with macrophage morphological features at the tumor margin. Little enhancement was seen in two other models. CONCLUSION These studies demonstrate the safety and efficacy of iron oxide-based MRI contrast agents in the brain and provide imaging parameters and time course data for future studies in brain tumors and neurological lesions.
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Affiliation(s)
- Leslie L Muldoon
- Department of Neurology, Oregon Health & Sciences University, Portland, Oregon, USA
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73
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Briley-Saebo KC, Johansson LO, Hustvedt SO, Haldorsen AG, Bjørnerud A, Fayad ZA, Ahlstrom HK. Clearance of Iron Oxide Particles in Rat Liver. Invest Radiol 2006; 41:560-71. [PMID: 16772849 DOI: 10.1097/01.rli.0000221321.90261.09] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We sought to evaluate the effect of the particle size and coating material of various iron oxide preparations on the rate of rat liver clearance. MATERIALS AND METHODS The following iron oxide formulations were used in this study: dextran-coated ferumoxide (size = 97 nm) and ferumoxtran-10 (size = 21 nm), carboxydextran-coated SHU555A (size = 69 nm) and fractionated SHU555A (size = 12 nm), and oxidized-starch coated materials either unformulated NC100150 (size = 15 nm) or formulated NC100150 injection (size = 12 nm). All formulations were administered to 165 rats at 2 dose levels. Quantitative liver R2* values were obtained during a 63-day time period. The concentration of iron oxide particles in the liver was determined by relaxometry, and these values were used to calculate the particle half-lives in the liver. RESULTS After the administration of a high dose of iron oxide, the half-life of iron oxide particles in rat liver was 8 days for dextran-coated materials, 10 days for carboxydextran materials, 14 days for unformulated oxidized-starch, and 29 days for formulated oxidized-starch. CONCLUSIONS The results of the study indicate that materials with similar coating but different sizes exhibited similar rates of liver clearance. It was, therefore, concluded that the coating material significantly influences the rate of iron oxide clearance in rat liver.
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Affiliation(s)
- Karen C Briley-Saebo
- Imaging Science Laboratories, Mount Sinai School of Medicine, New York, NY 10029, USA.
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74
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Abstract
BACKGROUND AND PURPOSE The simplistic view of atherosclerosis as a disorder of pathological lipid deposition has been redefined by the more complex concept of an ongoing inflammatory response. SUMMARY OF REVIEW Apolipoprotein E and low-density lipoprotein (LDL)-receptor-deficient mice develop accelerated atherosclerosis allowing in-depth pathophysiological investigations. Atherosclerotic plaques in these mice contain large numbers of T cells and macrophages. Crossbreeding apolipoprotein E-deficient mice with T-cell-deficient mice and mice with impaired macrophage function (osteopetrotic op/op mice) disclosed the important impact of immune cells on atherosclerotic lesion development. In contrast to the detrimental role of T cells and macrophages, B cells appear to be atheroprotective. These basic experimental findings have partly been confirmed in studies of the human carotid artery system. Inflammation is not only instrumental in the development of human atheromatous plaques, but, importantly, plays a crucial role in the destabilization of internal carotid artery plaques, thus converting chronic atherosclerosis into an acute thrombo-embolic disorder. Humoral factors involved in internal carotid artery destabilization include cytokines, cyclooxygenase-2, matrix metalloproteinases, and tissue factor. Antibodies to oxidized LDL can reflect disease activity on one hand, but can also confer atheroprotection. Novel MRI techniques may aid in the in vivo assessment of acute plaque inflammation in humans. CONCLUSIONS The impact of inflammation on the development of atherosclerotic plaques and their destabilization opens new avenues for treatment. The effects of statins, acetylsalicyclic acid and angiotensin-converting enzyme inhibitors on stroke prevention may partly be attributable to their profound anti-inflammatory actions. Vaccination against modified LDL and heat shock proteins halt plaque progression in experimental atherosclerosis. Their potential for prevention of human atherosclerosis is currently under investigation.
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MESH Headings
- Animals
- Anti-Inflammatory Agents/therapeutic use
- Apolipoproteins E/deficiency
- Apolipoproteins E/genetics
- Atherosclerosis/etiology
- Atherosclerosis/immunology
- Atherosclerosis/physiopathology
- Autoantibodies/immunology
- Carotid Artery Diseases/complications
- Carotid Artery Diseases/drug therapy
- Carotid Artery Diseases/pathology
- Crosses, Genetic
- Cytokines/antagonists & inhibitors
- Cytokines/physiology
- Endothelium, Vascular/injuries
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Female
- Heart Transplantation
- Humans
- Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use
- Inflammation/complications
- Inflammation/drug therapy
- Lipoproteins, LDL/immunology
- Macrophages/pathology
- Magnetic Resonance Imaging
- Male
- Mice
- Mice, Knockout
- Mice, SCID
- Models, Animal
- Osteopetrosis/genetics
- Osteopetrosis/immunology
- Postoperative Complications/immunology
- Postoperative Complications/pathology
- Protease Inhibitors/therapeutic use
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Severe Combined Immunodeficiency/genetics
- Severe Combined Immunodeficiency/immunology
- Stroke/etiology
- Stroke/prevention & control
- T-Lymphocytes/pathology
- Thromboembolism/etiology
- Thromboembolism/prevention & control
- Vaccination
- Vasculitis/complications
- Vasculitis/drug therapy
- Vasculitis/physiopathology
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Affiliation(s)
- Guido Stoll
- Department of Neurology, Julius-Maximilians-Universität, Würzburg, Germany.
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75
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Herborn CU, Vogt FM, Lauenstein TC, Dirsch O, Corot C, Robert P, Ruehm SG. Magnetic resonance imaging of experimental atherosclerotic plaque: Comparison of two ultrasmall superparamagnetic particles of iron oxide. J Magn Reson Imaging 2006; 24:388-93. [PMID: 16791857 DOI: 10.1002/jmri.20649] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE To evaluate a new ultrasmall superparamagnetic particles of iron oxide (USPIO) compound, ferumoxytol, as a marker of macrophage activity in atherosclerotic plaques and to compare it to ferumoxtran-10. MATERIALS AND METHODS Ten mature heritable hyperlipidemic (WHHL) female Watanabe rabbits served as the animal model for atherosclerosis, four coeval female New Zealand White (NZW) rabbits were the control group. Five WHHL and two NZW received a single intravenous injection (250 micromol/kg) of either ferumoxtran-10 or ferumoxytol and were subjected to daily MR examinations on a 1.5T whole body scanner for the next five days. Development of signal intensity changes and susceptibility effects was assessed. Statistical analysis was based on a nonparametric Wilcoxon-Mann-Whitney-U test by using a P value at the 0.05 significance level. On day 5, the rabbits were sacrificed and the aorta was referred to histopathology, distribution of iron particles in the vessel wall was analyzed. RESULTS MRI was feasible in all animals. Three days after injection of ferumoxytol the highest luminal signal intensity measurements were observed in the ferumoxytol group; the highest measurements were five days after injection in the ferumoxtran-10 group (P < 0.05). In the WHHL, susceptibility effects presented as homogeneous dark lines parallel to the aortic wall after ferumoxytol and spotted areas void of signal after ferumoxtran-10. None of these findings were observed in the NZW control groups. CONCLUSION Ferumoxtran-10 and ferumoxytol at a respective dose of 250 mumol/kg appear well suited for atherosclerotic plaque detection with MRI in experimental atherosclerosis. Ferumoxytol warrants further analysis in humans.
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Affiliation(s)
- Christoph U Herborn
- Medical Prevention Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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76
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Muldoon LL, Sàndor M, Pinkston KE, Neuwelt EA. Imaging, Distribution, and Toxicity of Superparamagnetic Iron Oxide Magnetic Resonance Nanoparticles in the Rat Brain and Intracerebral Tumor. Neurosurgery 2005. [DOI: 10.1227/01.neu.0000175731.25414.4c] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Leslie L. Muldoon
- Departments of Neurology and Cell and Developmental Biology, Oregon Health & Sciences University, Portland, Oregon
| | - Manninger Sàndor
- Departments of Neurology and Cell and Developmental Biology, Oregon Health & Sciences University, Portland, Oregon
| | | | - Edward A. Neuwelt
- Departments of Neurology and Neurosurgery, Oregon Health & Sciences University, and Department of Neurosurgery, Veterans Administration Medical Center, Portland, Oregon
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