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Yoo SP, Pineda F, Barrett JC, Poon C, Tirrell M, Chung EJ. Gadolinium-Functionalized Peptide Amphiphile Micelles for Multimodal Imaging of Atherosclerotic Lesions. ACS OMEGA 2016; 1:996-1003. [PMID: 27917409 PMCID: PMC5131325 DOI: 10.1021/acsomega.6b00210] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/09/2016] [Indexed: 05/23/2023]
Abstract
The leading causes of morbidity and mortality globally are cardiovascular diseases, and nanomedicine can provide many improvements including disease-specific targeting, early detection, and local delivery of diagnostic agents. To this end, we designed fibrin-binding, peptide amphiphile micelles (PAMs), achieved by incorporating the targeting peptide cysteine-arginine-glutamic acid-lysine-alanine (CREKA), with two types of amphiphilic molecules containing the gadoliniuim (Gd) chelator diethylenetriaminepentaacetic acid (DTPA), DTPA-bis(stearylamide)(Gd), and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[(poly(ethylene glycol) (PEG))-2000]-DTPA(Gd) (DSPE-PEG2000-DTPA(Gd)). The material characteristics of the resulting nanoparticle diagnostic probes, clot-binding properties in vitro, and contrast enhancement and safety for dual, optical imaging-magnetic resonance imaging (MRI) were evaluated in the atherosclerotic mouse model. Transmission electron micrographs showed a homogenous population of spherical micelles for formulations containing DSPE-PEG2000-DTPA(Gd), whereas both spherical and cylindrical micelles were formed upon mixing DTPA-BSA(Gd) and CREKA amphiphiles. Clot-binding assays confirmed DSPE-PEG2000-DTPA(Gd)-based CREKA micelles targeted clots over 8-fold higher than nontargeting (NT) counterpart micelles, whereas no difference was found between CREKA and NT, DTPA-BSA(Gd) micelles. However, in vivo MRI and optical imaging studies of the aortas and hearts showed fibrin specificity was conferred by the peptide ligand without much difference between the nanoparticle formulations or shapes. Biodistribution studies confirmed that all micelles were cleared through both the reticuloendothelial system and renal clearance, and histology showed no signs of necrosis. In summary, these studies demonstrate the successful synthesis, and the molecular imaging capabilities of two types of CREKA-Gd PAMs for atherosclerosis. Moreover, we demonstrate the differences in micelle formulations and shapes and their outcomes in vitro versus in vivo for site-specific, diagnostic strategies, and provide the groundwork for the detection of thrombosis via contrast-enhancing agents and concurrent therapeutic delivery for theranostic applications.
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Affiliation(s)
- Sang Pil Yoo
- Institute
for Molecular Engineering, University of
Chicago, 5747 South Ellis Avenue, Chicago, Illinois, 60637, United States
| | - Federico Pineda
- Department
of Radiology, University of Chicago, 5841 South Maryland Avenue, MC2026, Chicago, Illinois 60637, United States
| | - John C. Barrett
- Institute
for Molecular Engineering, University of
Chicago, 5747 South Ellis Avenue, Chicago, Illinois, 60637, United States
| | - Christopher Poon
- Department
of Chemistry, University of Chicago, 929 E. 57th Street, Chicago, Illinois 60637, United States
| | - Matthew Tirrell
- Institute
for Molecular Engineering, University of
Chicago, 5747 South Ellis Avenue, Chicago, Illinois, 60637, United States
| | - Eun Ji Chung
- Institute
for Molecular Engineering, University of
Chicago, 5747 South Ellis Avenue, Chicago, Illinois, 60637, United States
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Jacobs AH, Tavitian B. Noninvasive molecular imaging of neuroinflammation. J Cereb Blood Flow Metab 2012; 32:1393-415. [PMID: 22549622 PMCID: PMC3390799 DOI: 10.1038/jcbfm.2012.53] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 03/05/2012] [Accepted: 03/23/2012] [Indexed: 12/23/2022]
Abstract
Inflammation is a highly dynamic and complex adaptive process to preserve and restore tissue homeostasis. Originally viewed as an immune-privileged organ, the central nervous system (CNS) is now recognized to have a constant interplay with the innate and the adaptive immune systems, where resident microglia and infiltrating immune cells from the periphery have important roles. Common diseases of the CNS, such as stroke, multiple sclerosis (MS), and neurodegeneration, elicit a neuroinflammatory response with the goal to limit the extent of the disease and to support repair and regeneration. However, various disease mechanisms lead to neuroinflammation (NI) contributing to the disease process itself. Molecular imaging is the method of choice to try to decipher key aspects of the dynamic interplay of various inducers, sensors, transducers, and effectors of the orchestrated inflammatory response in vivo in animal models and patients. Here, we review the basic principles of NI with emphasis on microglia and common neurologic disease mechanisms, the molecular targets which are being used and explored for imaging, and molecular imaging of NI in frequent neurologic diseases, such as stroke, MS, neurodegeneration, epilepsy, encephalitis, and gliomas.
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Affiliation(s)
- Andreas H Jacobs
- European Institute for Molecular Imaging (EIMI) at the Westfalian Wilhelms-University of Münster (WWU), Münster, Germany.
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te Boekhorst BC, van Tilborg GA, Strijkers GJ, Nicolay K. Molecular MRI of Inflammation in Atherosclerosis. CURRENT CARDIOVASCULAR IMAGING REPORTS 2011; 5:60-68. [PMID: 22308200 PMCID: PMC3261392 DOI: 10.1007/s12410-011-9114-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Inflammatory activity in atherosclerotic plaque is a risk factor for plaque rupture and atherothrombosis and may direct interventional therapy. Inflammatory activity can be evaluated at the (sub)cellular level using in vivo molecular MRI. This paper reviews recent progress in contrast-enhanced molecular MRI to visualize atherosclerotic plaque inflammation. Various MRI contrast agents, among others ultra-small particles of iron oxide, low-molecular-weight Gd-chelates, micelles, liposomes, and perfluorocarbon emulsions, have been used for in vivo visualization of various inflammation-related targets, such as macrophages, oxidized LDL, endothelial cell expression, plaque neovasculature, MMPs, apoptosis, and activated platelets/thrombus. An enzyme-activatable magnetic resonance contrast agent has been developed to study myeloperoxidase activity in inflamed plaques. Agents creating contrast based on the chemical exchange saturation transfer mechanism were used for thrombus imaging. Transfer of these molecular MRI techniques to the clinic will critically depend on the safety profiles of these newly developed magnetic resonance contrast agents.
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Affiliation(s)
- Bernard C. te Boekhorst
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - Geralda A. van Tilborg
- Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center Utrecht, Yalelaan 2, 3584 CM Utrecht, The Netherlands
| | - Gustav J. Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
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