151
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Ito H. Integrated Imaging Functionality of Rare Earth Complexes via Ligand Architecture. J SYN ORG CHEM JPN 2012. [DOI: 10.5059/yukigoseikyokaishi.70.276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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152
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He C, Wu X, Kong J, liu T, Zhang X, Duan C. A hexanuclear gadolinium–organic octahedron as a sensitive MRI contrast agent for selectively imaging glucosamine in aqueous media. Chem Commun (Camb) 2012; 48:9290-2. [DOI: 10.1039/c2cc33177b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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153
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Li WS, Luo J, Chen ZN. A self-assembly heterotrinuclear gadolinium(III)–iron(II) complex as a MRI contrast agent. INORG CHEM COMMUN 2011. [DOI: 10.1016/j.inoche.2011.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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154
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Noninvasive MRI of β-cell function using a Zn2+-responsive contrast agent. Proc Natl Acad Sci U S A 2011; 108:18400-5. [PMID: 22025712 DOI: 10.1073/pnas.1109649108] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Elevation of postprandial glucose stimulates release of insulin from granules stored in pancreatic islet β-cells. We demonstrate here that divalent zinc ions coreleased with insulin from β-cells in response to high glucose are readily detected by MRI using the Zn(2+)-responsive T(1) agent, GdDOTA-diBPEN. Image contrast was significantly enhanced in the mouse pancreas after injection of a bolus of glucose followed by a low dose of the Zn(2+) sensor. Images of the pancreas were not enhanced by the agent in mice without addition of glucose to stimulate insulin release, nor were images enhanced in streptozotocin-treated mice with or without added glucose. These observations are consistent with MRI detection of Zn(2+) released from β-cells only during glucose-stimulated insulin secretion. Images of mice fed a high-fat (60%) diet over a 12-wk period and subjected to this same imaging protocol showed a larger volume of contrast-enhanced pancreatic tissue, consistent with the expansion of pancreatic β-cell mass during fat accumulation and progression to type 2 diabetes. This MRI sensor offers the exciting potential for deep-tissue monitoring of β-cell function in vivo during development of type 2 diabetes or after implantation of islets in type I diabetic patients.
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155
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156
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Ai H. Layer-by-layer capsules for magnetic resonance imaging and drug delivery. Adv Drug Deliv Rev 2011; 63:772-88. [PMID: 21554908 DOI: 10.1016/j.addr.2011.03.013] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 01/20/2011] [Accepted: 03/30/2011] [Indexed: 12/30/2022]
Abstract
Layer-by-layer (LbL) self-assembled polyelectrolyte capsules have demonstrated their unique advantages and capability in drug delivery applications. These ordered micro/nano-structures are also promising candidates as imaging contrast agents for diagnostic and theranostic applications. Magnetic resonance imaging (MRI), one of the most powerful clinical imaging modalities, is moving forward to the molecular imaging field and requires the availability of advanced imaging probes. In this review, we are focusing on the design of MRI visible LbL capsules, which incorporate either paramagnetic metal-ligand complexes or superparamagnetic iron oxide (SPIO) nanoparticles. The design criteria cover the topics of probe sensitivity, biosafety, long-circulation property, targeting ligand decoration, and drug loading strategies. Examples of MRI visible LbL capsules with paramagnetic or superparamagnetic moieties were given and discussed. This carrier platform can also be chosen for other imaging modalities.
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Affiliation(s)
- Hua Ai
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China.
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157
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Park C, Lee J, Kim C. Functional supramolecular assemblies derived from dendritic building blocks. Chem Commun (Camb) 2011; 47:12042-56. [PMID: 21785775 DOI: 10.1039/c1cc11531f] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Control of the structure and function of self-assembled materials has been a significant issue in many areas of nanoscience. Among many different types of building blocks, dendritic ones have shown interesting self-assembly behaviour and functional performances due to their unique shape and multiple functionalities. Dendritic building blocks exhibit unique self-assembly behaviour in diverse environments such as aqueous and organic solutions, solid-liquid interfaces, and thermotropic solid conditions. Tuning the balance between hydrophilic and hydrophobic parts, as well as the external conditions for self-assembly, provides unique opportunities for control of supramolecular architectures. Furthermore, the introduction of suitable functional moieties into dendrons enables us to control self-assembly characteristics, allowing nanostructures to exhibit smart performances for electronic or biological applications. The self-assembly characteristics of amphiphilic dendrons under various conditions were investigated to elucidate how dendrons can assemble into nanoscopic structures and how these nanoassemblies exhibit unique properties. Well-defined nanostructures derived from self-assembly of dendrons provide an efficient approach for exhibition of unique functions at the nanoscale. This feature article describes the unique self-assembly characteristics of various types of dendritic building blocks and their potential applications as advanced materials.
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Affiliation(s)
- Chiyoung Park
- Department of Polymer Science and Engineering, Inha University, Incheon 402-751, Korea
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158
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Waukau J, Woodliff J, Glisic S. Human in vitro suppression as screening tool for the recognition of an early state of immune imbalance. J Vis Exp 2011:3071. [PMID: 21808226 DOI: 10.3791/3071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Regulatory T cells (Tregs) are critical mediators of immune tolerance to self-antigens. In addition, they are crucial regulators of the immune response following an infection. Despite efforts to identify unique surface marker on Tregs, the only unique feature is their ability to suppress the proliferation and function of effector T cells. While it is clear that only in vitro assays can be used in assessing human Treg function, this becomes problematic when assessing the results from cross-sectional studies where healthy cells and cells isolated from subjects with autoimmune diseases (like Type 1 Diabetes-T1D) need to be compared. There is a great variability among laboratories in the number and type of responder T cells, nature and strength of stimulation, Treg:responder ratios and the number and type of antigen-presenting cells (APC) used in human in vitro suppression assays. This variability makes comparison between studies measuring Treg function difficult. The Treg field needs a standardized suppression assay that will work well with both healthy subjects and those with autoimmune diseases. We have developed an in vitro suppression assay that shows very little intra-assay variability in the stimulation of T cells isolated from healthy volunteers compared to subjects with underlying autoimmune destruction of pancreatic β-cells. The main goal of this piece is to describe an in vitro human suppression assay that allows comparison between different subject groups. Additionally, this assay has the potential to delineate a small loss in nTreg function and anticipate further loss in the future, thus identifying subjects who could benefit from preventive immunomodulatory therapy. Below, we provide thorough description of the steps involved in this procedure. We hope to contribute to the standardization of the in vitro suppression assay used to measure Treg function. In addition, we offer this assay as a tool to recognize an early state of immune imbalance and a potential functional biomarker for T1D.
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Affiliation(s)
- Jill Waukau
- Department of Pediatrics/Allergy, Medical College of Wisconsin, USA
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159
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Averill DJ, Garcia J, Siriwardena-Mahanama BN, Vithanarachchi SM, Allen MJ. Preparation, purification, and characterization of lanthanide complexes for use as contrast agents for magnetic resonance imaging. J Vis Exp 2011:2844. [PMID: 21808225 DOI: 10.3791/2844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Polyaminopolycarboxylate-based ligands are commonly used to chelate lanthanide ions, and the resulting complexes are useful as contrast agents for magnetic resonance imaging (MRI). Many commercially available ligands are especially useful because they contain functional groups that allow for fast, high-purity, and high-yielding conjugation to macromolecules and biomolecules via amine-reactive activated esters and isothiocyanate groups or thiol-reactive maleimides. While metalation of these ligands is considered common knowledge in the field of bioconjugation chemistry, subtle differences in metalation procedures must be taken into account when selecting metal starting materials. Furthermore, multiple options for purification and characterization exist, and selection of the most effective procedure partially depends on the selection of starting materials. These subtle differences are often neglected in published protocols. Here, our goal is to demonstrate common methods for metalation, purification, and characterization of lanthanide complexes that can be used as contrast agents for MRI (Figure 1). We expect that this publication will enable biomedical scientists to incorporate lanthanide complexation reactions into their repertoire of commonly used reactions by easing the selection of starting materials and purification methods.
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160
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Abstract
Some of the most exciting advances in molecular-functional imaging of cancer are occurring at the interface between chemistry and imaging. Several of these advances have occurred through the development of novel imaging probes that report on molecular pathways, the tumor micro-environment and the response of tumors to treatment; as well as through novel image-guided platforms such as nanoparticles and nanovesicles that deliver therapeutic agents against specific targets and pathways. Cancer cells have a remarkable ability to evade destruction despite the armamentarium of drugs currently available. While these drugs can destroy cancer cells, normal tissue toxicity is a major limiting factor, a problem further compounded by poor drug delivery. One major challenge for chemistry continues to be to eliminate cancer cells without damaging normal tissues. Here we have selected examples of MRI and optical imaging, to demonstrate how integrating imaging with novel probes can facilitate the successful treatment of this multifaceted disease.
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161
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Abstract
Given the important role of metal ions in fundamental biological processes, the visualization of their concentration in living animals by repeatable, noninvasive imaging techniques, such as MRI, would be highly desirable. A large number of metal-responsive MRI contrast agents, the majority based on Gd(3+) complexes, have been reported in recent years. The contrast-enhancing properties (relaxivity) of a Gd(3+) complex can be most conveniently modulated by interaction with the sensed metal cation via changes in the number of water molecules bound directly to Gd(3+) or changes in the size of the complex, which represent the two major strategies to develop metal sensitive MRI probes. Here, we survey paramagnetic lanthanide complexes involving Gd(3+) agents and paramagnetic chemical exchange saturation transfer probes designed to detect the most important endogenous metal ions: calcium, zinc, iron and copper. Future work will likely focus on extending applications of these agents to living animals, as well as on exploring new ways of creating molecular MRI probes in order to meet requirements such as higher specificity or lower detection limits.
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162
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Hammell J, Buttarazzi L, Huang CH, Morrow JR. Eu(III) complexes as anion-responsive luminescent sensors and paramagnetic chemical exchange saturation transfer agents. Inorg Chem 2011; 50:4857-67. [PMID: 21548563 PMCID: PMC3528016 DOI: 10.1021/ic200075w] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The Eu(III) complex of (1S,4S,7S,10S)-1,4,7,10-tetrakis(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane (S-THP) is studied as a sensor for biologically relevant anions. Anion interactions produce changes in the luminescence emission spectrum of the Eu(III) complex, in the (1)H NMR spectrum, and correspondingly, in the PARACEST spectrum of the complex (PARACEST = paramagnetic chemical exchange saturation transfer). Direct excitation spectroscopy and luminescence lifetime studies of Eu(S-THP) give information about the speciation and nature of anion interactions including carbonate, acetate, lactate, citrate, phosphate, and methylphosphate at pH 7.2. Data is consistent with the formation of both innersphere and outersphere complexes of Eu(S-THP) with acetate, lactate, and carbonate. These anions have weak dissociation constants that range from 19 to 38 mM. Citrate binding to Eu(S-THP) is predominantly innersphere with a dissociation constant of 17 μM. Luminescence emission peak changes upon addition of anion to Eu(S-THP) show that there are two distinct binding events for phosphate and methylphosphate with dissociation constants of 0.3 mM and 3.0 mM for phosphate and 0.6 mM and 9.8 mM for methyl phosphate. Eu(THPC) contains an appended carbostyril derivative as an antenna to sensitize Eu(III) luminescence. Eu(THPC) binds phosphate and citrate with dissociation constants that are 10-fold less than that of the Eu(S-THP) parent, suggesting that functionalization through a pendent group disrupts the anion binding site. Eu(S-THP) functions as an anion responsive PARACEST agent through exchange of the alcohol protons with bulk water. The alcohol proton resonances of Eu(S-THP) shift downfield in the presence of acetate, lactate, citrate, and methylphosphate, giving rise to distinct PARACEST peaks. In contrast, phosphate binds to Eu(S-THP) to suppress the PARACEST alcohol OH peak and carbonate does not markedly change the alcohol peak at 5 mM Eu(S-THP), 15 mM carbonate at pH 6.5 or 7.2. This work shows that the Eu(S-THP) complex has unique selectivity toward binding of biologically relevant anions and that anion binding results in changes in both the luminescence and the PARACEST spectra of the complex.
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Affiliation(s)
- Jacob Hammell
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, NY 14260-3000
| | - Leandro Buttarazzi
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, NY 14260-3000
| | - Ching-Hui Huang
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, NY 14260-3000
| | - Janet R. Morrow
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, NY 14260-3000
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163
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Longo DL, Dastrù W, Digilio G, Keupp J, Langereis S, Lanzardo S, Prestigio S, Steinbach O, Terreno E, Uggeri F, Aime S. Iopamidol as a responsive MRI-chemical exchange saturation transfer contrast agent for pH mapping of kidneys: In vivo studies in mice at 7 T. Magn Reson Med 2011; 65:202-11. [PMID: 20949634 DOI: 10.1002/mrm.22608] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Iopamidol (Isovue®-Bracco Diagnostic Inc.) is a clinically approved X-Ray contrast agent used in the last 30 years for a wide variety of diagnostic applications with a very good clinical acceptance. Iopamidol contains two types of amide functionalities that can be exploited for the generation of chemical exchange saturation transfer effect. The exchange rate of the two amide proton pools is markedly pH-dependent. Thus, a ratiometric method for pH assessment has been set-up based on the comparison of the saturation transfer effects induced by selective irradiation of the two resonances. This ratiometric approach allows to rule out the concentration effect of the contrast agent and provides accurate pH measurements in the 5.5-7.4 range. Upon injection of Iopamidol into healthy mice, it has been possible to acquire pH maps of kidney regions. Furthermore, it has been also shown that the proposed method is able to report about pH-changes induced in control mice fed with acidified or basified water for a period of a week before image acquisition.
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Affiliation(s)
- Dario Livio Longo
- Department of Chemistry IFM and Center for Molecular Imaging, University of Torino, Torino, Italy
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164
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Mastarone DJ, Harrison VS, Eckermann AL, Parigi G, Luchinat C, Meade TJ. A modular system for the synthesis of multiplexed magnetic resonance probes. J Am Chem Soc 2011; 133:5329-37. [PMID: 21413801 PMCID: PMC3086647 DOI: 10.1021/ja1099616] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have developed a modular architecture for preparing high-relaxivity multiplexed probes utilizing click chemistry. Our system incorporates azide bearing Gd(III) chelates and a trialkyne scaffold with a functional group for subsequent modification. In optimizing the relaxivity of this new complex, we undertook a study of the linker length between a chelate and the scaffold to determine its effect on relaxivity. The results show a strong dependence on flexibility between the individual chelates and the scaffold with decreasing linker length leading to significant increases in relaxivity. Nuclear magnetic resonance dispersion (NMRD) spectra were obtained to confirm a 10-fold increase in the rotational correlation time from 0.049 to 0.60 ns at 310 K. We have additionally obtained a crystal structure demonstrating that modification with an azide does not impact the coordination of the lanthanide. The resulting multinuclear center has a 500% increase in per Gd (or ionic) relaxivity at 1.41 T versus small molecule contrast agents and a 170% increase in relaxivity at 9.4 T.
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Affiliation(s)
- Daniel J. Mastarone
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Victoria S.R. Harrison
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Amanda L. Eckermann
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Giacomo Parigi
- CERM and Department of Chemistry, University of Florence, Florence, Italy
| | - Claudio Luchinat
- CERM and Department of Chemistry, University of Florence, Florence, Italy
| | - Thomas J. Meade
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
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165
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Shen Y, Ma X, Zhang B, Zhou Z, Sun Q, Jin E, Sui M, Tang J, Wang J, Fan M. Degradable Dual pH‐ and Temperature‐Responsive Photoluminescent Dendrimers. Chemistry 2011; 17:5319-26. [DOI: 10.1002/chem.201003495] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Indexed: 12/29/2022]
Affiliation(s)
- Youqing Shen
- Center for Bionanoengineering and State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, 310027 (P.R. China), Fax: (+86) 571‐87953993
- Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (USA)
| | - Xinpeng Ma
- Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (USA)
| | - Bo Zhang
- Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (USA)
| | - Zhuxian Zhou
- Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (USA)
| | - Qihang Sun
- Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (USA)
| | - Erlei Jin
- Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (USA)
| | - Meihua Sui
- Center for Bionanoengineering and State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, 310027 (P.R. China), Fax: (+86) 571‐87953993
| | - Jianbin Tang
- Center for Bionanoengineering and State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, 310027 (P.R. China), Fax: (+86) 571‐87953993
| | - Jinqiang Wang
- Center for Bionanoengineering and State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou, 310027 (P.R. China), Fax: (+86) 571‐87953993
| | - Maohong Fan
- Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, WY 82071 (USA)
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166
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Regueiro-Figueroa M, Bensenane B, Ruscsák E, Esteban-Gómez D, Charbonnière LJ, Tircsó G, Tóth I, de Blas A, Rodríguez-Blas T, Platas-Iglesias C. Lanthanide dota-like complexes containing a picolinate pendant: structural entry for the design of Ln(III)-based luminescent probes. Inorg Chem 2011; 50:4125-41. [PMID: 21456610 DOI: 10.1021/ic2001915] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In this contribution we present two ligands based on a do3a platform containing a picolinate group attached to the fourth nitrogen atom of the cyclen unit, which are designed for stable lanthanide complexation in aqueous solutions. Potentiometric measurements reveal that the thermodynamic stability of the complexes is very high (log K = 21.2-23.5), being comparable to that of the dota analogues. Luminescence lifetime measurements performed on solutions of the Eu(III) and Tb(III) complexes indicate that the complexes are nine coordinate with no inner-sphere water molecules. A combination of density functional theory (DFT) calculations and NMR measurements shows that for the complexes of the heaviest lanthanides there is a major isomer in solution consisting of the enantiomeric pair Λ(δδδδ) and Δ(λλλλ), which provides square antiprismatic coordination (SAP) around the metal ion. Analysis of the Yb(III)-induced paramagnetic shifts unambiguously confirms that these complexes have SAP coordination in aqueous solution. For the light lanthanide ions however both the SAP and twisted-square antiprismatic (TSAP) isomers are present in solution. Inversion of the cyclen ring appears to be the rate-determining step for the Λ(δδδδ) ↔ Δ(λλλλ) enantiomerization process observed in the Lu(III) complexes. The energy barriers obtained from NMR measurements for this dynamic process are in excellent agreement with those predicted by DFT calculations. The energy barriers calculated for the arm-rotation process are considerably lower than those obtained for the ring-inversion path. Kinetic studies show that replacement of an acetate arm of dota by a picolinate pendant results in a 3-fold increase in the formation rate of the corresponding Eu(III) complexes and a significant increase of the rates of acid-catalyzed dissociation of the complexes. However, these rates are 1-2 orders of magnitude lower than those of do3a analogues, which shows that the complexes reported herein are remarkably inert with respect to metal ion dissociation.
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Affiliation(s)
- Martín Regueiro-Figueroa
- Departamento de Química Fundamental, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
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167
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Weerasekare M, Taraban MB, Shi X, Jeong EK, Trewhella J, Yu YB. Sol and gel states in peptide hydrogels visualized by Gd(III)-enhanced magnetic resonance imaging. Biopolymers 2011; 96:734-43. [PMID: 22252424 PMCID: PMC3616518 DOI: 10.1002/bip.21612] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 02/21/2011] [Accepted: 02/22/2011] [Indexed: 01/04/2023]
Abstract
The hydrogels assembled from a pair of self-repulsive but mutually attractive decapeptides are visualized by magnetic resonance imaging (MRI). It is found that in the absence of Gd(III)-chelate, gelation has little effect on MRI signal intensity. In the presence of Gd(III)-chelate, gelation leads to significant changes in water relaxation and MR signal intensity. The sol to gel transition is best visualized by T2-weighted imaging using large echo time with the sol producing a bright spot and the gel producing a dark spot. MRI studies point to high local Gd(III)-chelate concentration. Small-angle X-ray scattering study indicates that this local enrichment of Gd(III)-chelate has two contributing processes: first, the aggregation of peptides into fibers; second, within peptide fibers, Gd(III)-chelate further aggregate into clusters. This work demonstrates that the status of peptide-based hydrogels can be visualized by MRI with the aid of covalently linked Gd(III)-chelates. This result has implications for monitoring peptide scaffolds in vivo.
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Affiliation(s)
| | | | | | | | | | - Yihua Bruce Yu
- To whom correspondence should be addressed. Current address of corresponding author: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA, tel 301-405-2829, fax 301-315-9953 or Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD 21201, USA; , tel 410-706-7514, fax 410-706-5017
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168
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Tu C, Osborne EA, Louie AY. Activatable T₁ and T₂ magnetic resonance imaging contrast agents. Ann Biomed Eng 2011; 39:1335-48. [PMID: 21331662 PMCID: PMC3069332 DOI: 10.1007/s10439-011-0270-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 02/04/2011] [Indexed: 12/25/2022]
Abstract
Magnetic resonance imaging (MRI) has become one of the most important diagnosis tools available in medicine. Typically MRI is not capable of sensing biochemical activities. However, recently emerged activatable MRI contrast agents (CAs), whose relaxivity is variable in response to a specific parameter change in the surrounding physiological microenvironment, potentially allow for MRI to indicate biological processes. Among the various factors influencing the relaxivity of a CA, the number of inner-sphere water molecules (q) directly coordinated to the metal center, the residence time of the coordinated water molecule (τ (m)), and the rotational correlation time representing the molecular tumbling time of a complex (τ (R)) contribute strongly to the relaxivity of an activatable CA. Tuning the ligand structure and properties has been the subject of intensive research for activatable MR CA designs. This review summarizes a variety of activatable MRI CAs sensitive to common variables in microenvironment in vivo, i.e., pH, luminescence, metal ions, redox, and enzymes, etc., with emphasis on the influence of ligand design on parameters q, τ (m), and τ (R).
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Affiliation(s)
- Chuqiao Tu
- Department of Biomedical Engineering, University of California, Davis, CA, 95616, USA
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169
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Martinelli J, Fekete M, Tei L, Botta M. Cleavable β-cyclodextrin nanocapsules incorporating Gd(III)-chelates as bioresponsive MRI probes. Chem Commun (Camb) 2011; 47:3144-6. [PMID: 21270985 DOI: 10.1039/c0cc05428c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Perthiolated β-cyclodextrin-based nanocapsules incorporating diaquo Gd(III)-complexes represent a promising new type of bioresponsive MRI contrast agent, showing a pronounced relaxivity change upon degradation in a reducing environment.
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Affiliation(s)
- Jonathan Martinelli
- Dipartimento di Scienze dell'Ambiente e della Vita, Università del Piemonte Orientale Amedeo Avogadro, Viale T. Michel 11, 15121 Alessandria, Italy
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170
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Zhu H, Jones CK, van Zijl PCM, Barker PB, Zhou J. Fast 3D chemical exchange saturation transfer (CEST) imaging of the human brain. Magn Reson Med 2011; 64:638-44. [PMID: 20632402 DOI: 10.1002/mrm.22546] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Chemical exchange saturation transfer magnetic resonance imaging can detect low-concentration compounds with exchangeable protons through saturation transfer to water. This technique is generally slow, as it requires acquisition of saturation images at multiple frequencies. In addition, multislice imaging is complicated by saturation effects differing from slice to slice because of relaxation losses. In this study, a fast three-dimensional chemical exchange saturation transfer imaging sequence is presented that allows whole-brain coverage for a frequency-dependent saturation spectrum (z-spectrum, 26 frequencies) in less than 10 min. The approach employs a three-dimensional gradient- and spin-echo readout using a prototype 32-channel phased-array coil, combined with two-dimensional sensitivity encoding accelerations. Results from a homogenous protein-containing phantom at 3T show that the sequence produced a uniform contrast across all slices. To show translational feasibility, scans were also performed on five healthy human subjects. Results for chemical exchange saturation transfer images at 3.5 ppm downfield of the water resonance, so-called amide proton transfer images, show that lipid signals are sufficiently suppressed and artifacts caused by B(0) inhomogeneity can be removed in postprocessing. The scan time and image quality of these in vivo results show that three-dimensional chemical exchange saturation transfer MRI using gradient- and spin-echo acquisition is feasible for whole-brain chemical exchange saturation transfer studies at 3T in a clinical time frame.
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Affiliation(s)
- He Zhu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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171
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De León-Rodríguez LM, Viswanathan S, Sherry AD. Improved synthesis of DOTA tetraamide ligands for lanthanide(III) ions: a tool for increasing the repertoire of potential PARACEST contrast agents for MRI and/or fluorescent sensors. CONTRAST MEDIA & MOLECULAR IMAGING 2011; 5:121-5. [PMID: 20586036 DOI: 10.1002/cmmi.371] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The synthesis of new DOTA tetraamide (DOTAMR(4)) compounds is of great interest given their application in the formation of Ln(III) complexes as potential PARACEST contrast agents in MRI or fluorescent molecular probes. In this context amino acid and peptide DOTAMR(4) derivatives are particularly attractive since the amino-acid and/or peptide moiety can show responsive properties dependent on a given stimuli which might translate to changes in water exchange rates of the corresponding Ln(III) complex. Current synthesis of DOTAMR(4) derivatives is typically carried out by reacting haloacetamide intermediates with cyclen. However, this method fails to generate the tetra-substituted products when bulky substituents are present in the haloacetamide and in some cases this intermediate cannot be prepared by conventional acylation procedures limiting the number of DOTAMR(4) compounds available for study. As a solution to these limitations, an improved methodology for the synthesis of DOTAMR(4) by coupling DOTA to an appropriate amine containing reagent (i.e. protected amino-acids with the alpha-amino group free) is presented in this work. Several DOTAMR(4) derivatives which are difficult or impossible to prepare with the traditional methodologies were easily obtained starting with DOTA. A new protocol was derived using this methodology for the solution-phase synthesis of DOTA peptide derivatives. With this methodology, many other DOTAMR(4) peptide and non-peptide derivatives have been prepared in our laboratories with several of these new compounds showing interesting properties for molecular imaging.
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Affiliation(s)
- Luis M De León-Rodríguez
- Departamento de Química, Universidad de Guanajuato, Cerro de la Venada s/n, Guanajuato, Gto, C.P. 36040, Mexico.
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172
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Shazeeb MS, Sotak CH, DeLeo M, Bogdanov A. Targeted signal-amplifying enzymes enhance MRI of EGFR expression in an orthotopic model of human glioma. Cancer Res 2011; 71:2230-9. [PMID: 21245103 DOI: 10.1158/0008-5472.can-10-1139] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Epidermal growth factor receptor (EGFR) imaging in brain tumors is essential to visualize overexpression of EGFRvIII variants as a signature of highly aggressive gliomas and to identify patients that would benefit from anti-EGFR therapy. Seeking imaging improvements, we tested a novel pretargeting approach that relies on initial administration of enzyme-linked anti-EGFR monoclonal antibodies (mAb; EMD72000) followed by administration of a low-molecular-weight paramagnetic molecule (diTyr-GdDTPA) retained at the site of EGFR mAb accumulation. We hypothesized that diTyr-GdDTPA would become enzyme activated and retained on cells due to binding to tissue proteins. In support of this hypothesis, mAb-enzyme conjugates reacted with both membrane-isolated wild-type (wt) EGFR and EGFRvIII, but they bound primarily to EGFRvIII-expressing cells and not to EGFRwt-expressing cells. In vivo analysis of magnetic resonance (MR) tumor signal revealed differences in MR signal decay following diTyr-GdDTPA substrate administration. These differences were significant in that they suggested differences in substrate elimination from the tissue which relied on the specificity of the initial mAb binding: a biexponential signal decay was observed in tumors only upon preinjection with EGFR-targeted conjugates. Endpoint MRI in this setting revealed detailed images of tumors which correlated with immunohistochemical detection of EGFR expression. Together, our findings suggest an improved method to identify EGFRvIII-expressing gliomas in vivo that are best suited for treatment with therapeutic EGFR antibodies.
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Affiliation(s)
- Mohammed S Shazeeb
- Department of Biomedical Engineering, Worcester Polytechnic Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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173
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Delli Castelli D, Terreno E, Aime S. Yb(III)-HPDO3A: a dual pH- and temperature-responsive CEST agent. Angew Chem Int Ed Engl 2011; 50:1798-800. [PMID: 21328642 DOI: 10.1002/anie.201007105] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Indexed: 12/25/2022]
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174
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Delli Castelli D, Terreno E, Aime S. YbIII-HPDO3A: A Dual pH- and Temperature-Responsive CEST Agent. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201007105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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175
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Plaxco KW, Soh HT. Switch-based biosensors: a new approach towards real-time, in vivo molecular detection. Trends Biotechnol 2011; 29:1-5. [PMID: 21106266 PMCID: PMC3010506 DOI: 10.1016/j.tibtech.2010.10.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 10/18/2010] [Accepted: 10/25/2010] [Indexed: 01/21/2023]
Abstract
Although the ability to monitor specific molecules in vivo in real-time could revolutionize many aspects of healthcare, the technological challenges that stand in the way of reaching this goal are considerable and are poorly met by most existing analytical approaches. Nature, however, has already solved the problem of real-time molecular detection in complex media by employing biomolecular "switches". That is, protein and nucleic acids that sense chemical cues and, by undergoing specific, binding-induced conformational changes, transduce this recognition into high-gain signal outputs. Here, we argue that devices that employ such switches represent a promising route towards versatile, real-time molecular monitoring in vivo.
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Affiliation(s)
- Kevin W Plaxco
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
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176
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Li WS, Luo J, Chen ZN. A gadolinium(III) complex with 8-amidequinoline based ligand as copper(II) ion responsive contrast agent. Dalton Trans 2011; 40:484-8. [DOI: 10.1039/c0dt01141j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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177
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Ryan RO. Nanobiotechnology applications of reconstituted high density lipoprotein. J Nanobiotechnology 2010; 8:28. [PMID: 21122135 PMCID: PMC3004818 DOI: 10.1186/1477-3155-8-28] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 12/01/2010] [Indexed: 01/23/2023] Open
Abstract
High-density lipoprotein (HDL) plays a fundamental role in the Reverse Cholesterol Transport pathway. Prior to maturation, nascent HDL exist as disk-shaped phospholipid bilayers whose perimeter is stabilized by amphipathic apolipoproteins. Methods have been developed to generate reconstituted (rHDL) in vitro and these particles have been used in a variety of novel ways. To differentiate between physiological HDL particles and non-natural rHDL that have been engineered to possess additional components/functions, the term nanodisk (ND) is used. In this review, various applications of ND technology are described, such as their use as miniature membranes for solubilization and characterization of integral membrane proteins in a native like conformation. In other work, ND harboring hydrophobic biomolecules/drugs have been generated and used as transport/delivery vehicles. In vitro and in vivo studies show that drug loaded ND are stable and possess potent biological activity. A third application of ND is their use as a platform for incorporation of amphiphilic chelators of contrast agents, such as gadolinium, used in magnetic resonance imaging. Thus, it is demonstrated that the basic building block of plasma HDL can be repurposed for alternate functions.
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Affiliation(s)
- Robert O Ryan
- Center for Prevention of Obesity, Cardiovascular Disease and Diabetes, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr, Way, Oakland CA 94609, USA.
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178
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Martinelli J, Balali-Mood B, Panizzo R, Lythgoe MF, White AJP, Ferretti P, Steinke JHG, Vilar R. Coordination chemistry of amide-functionalised tetraazamacrocycles: structural, relaxometric and cytotoxicity studies. Dalton Trans 2010; 39:10056-67. [PMID: 20877892 DOI: 10.1039/c0dt00815j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Three different tetraazamacrocyclic ligands containing four amide substituents that feature groups (namely allyl, styryl and propargyl groups) suitable for polymerisation have been synthesised. Gadolinium(III) complexes of these three ligands have been prepared as potential monomers for the synthesis of polymeric MRI contrast agents. To assess the potential of these monomers as MRI contrast agents, their relaxation enhancement properties and cytotoxicity have been determined. A europium(III) complex of one of these ligands (with propargyl substituents) is also presented together with its PARACEST properties. In addition, to gain further insight into the coordination chemistry of the tetra-propargyl substituted ligand, the corresponding zinc(II) and cadmium(II) complexes have been prepared. The X-ray crystal structures of the tetra-propargyl ligand and its corresponding gadolinium(III), zinc(II) and cadmium(II) complexes are also presented.
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179
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Oostendorp M, Douma K, Hackeng TM, van Zandvoort MAMJ, Post MJ, Backes WH. Pharmacokinetics of contrast agents targeted to the tumor vasculature in molecular magnetic resonance imaging. CONTRAST MEDIA & MOLECULAR IMAGING 2010; 5:9-17. [PMID: 20101742 DOI: 10.1002/cmmi.361] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Molecular magnetic resonance imaging (MRI) is increasingly used to investigate tumor angiogenic activity non-invasively. However, the pharmacokinetic behavior and tumor penetration of the often large contrast agent particles is thus far unknown. Here, pharmacokinetic analysis of cyclic asparagine-glycine-arginine (cNGR) labeled paramagnetic quantum dots (pQDs) was developed to quantify the contrast agent's homing efficacy to activated endothelial cells of angiogenic tumor vessels using dynamic contrast-enhanced (DCE) MRI. cNGR homes to CD13, an overexpressed aminopeptidase on angiogenic tumor endothelial cells. First, a two-compartment pharmacokinetic model, comprising the blood space and endothelial cell surface, was compared with a three-compartment model additionally including the extravascular-extracellular component. The resulting extravasation parameter was irrelevantly small and was therefore neglected. Next, the association constant K(a), the dissociation constant k(d) and the fractional plasma volume v(P) were determined from the time-series data using the two-compartment model. Magnitude and spatial distribution of the parameters were compared for cNGR-labeled and unlabeled pQDs. The tumor area with significant K(a) values was approximately twice as large for cNGR-pQDs compared with unlabeled pQDs (p < 0.05), indicating more contrast agent binding for cNGR-pQDs. Using cNGR-pQDs, a two-fold larger area with significant K(a) was also found for the angiogenic tumor rim compared with tumor core (p < 0.05). It was furthermore found that both contrast agents perfused the tumor at all depths, thereby providing unequivocal evidence that rim/core differences can indeed be ascribed to stronger angiogenic activity in the rim. Summarizing, molecular DCE-MRI with pharmacokinetic modeling provides unique information on contrast agent delivery and angiogenic activity in tumors.
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Affiliation(s)
- Marlies Oostendorp
- Department of Radiology, Maastricht University Medical Centre (MUMC), Maastricht, The Netherlands
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180
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Dunn WB, Broadhurst DI, Atherton HJ, Goodacre R, Griffin JL. Systems level studies of mammalian metabolomes: the roles of mass spectrometry and nuclear magnetic resonance spectroscopy. Chem Soc Rev 2010; 40:387-426. [PMID: 20717559 DOI: 10.1039/b906712b] [Citation(s) in RCA: 557] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The study of biological systems in a holistic manner (systems biology) is increasingly being viewed as a necessity to provide qualitative and quantitative descriptions of the emergent properties of the complete system. Systems biology performs studies focussed on the complex interactions of system components; emphasising the whole system rather than the individual parts. Many perturbations to mammalian systems (diet, disease, drugs) are multi-factorial and the study of small parts of the system is insufficient to understand the complete phenotypic changes induced. Metabolomics is one functional level tool being employed to investigate the complex interactions of metabolites with other metabolites (metabolism) but also the regulatory role metabolites provide through interaction with genes, transcripts and proteins (e.g. allosteric regulation). Technological developments are the driving force behind advances in scientific knowledge. Recent advances in the two analytical platforms of mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy have driven forward the discipline of metabolomics. In this critical review, an introduction to metabolites, metabolomes, metabolomics and the role of MS and NMR spectroscopy will be provided. The applications of metabolomics in mammalian systems biology for the study of the health-disease continuum, drug efficacy and toxicity and dietary effects on mammalian health will be reviewed. The current limitations and future goals of metabolomics in systems biology will also be discussed (374 references).
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Affiliation(s)
- Warwick B Dunn
- Manchester Centre for Integrative Systems Biology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
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181
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Terreno E, Castelli DD, Viale A, Aime S. Challenges for molecular magnetic resonance imaging. Chem Rev 2010; 110:3019-42. [PMID: 20415475 DOI: 10.1021/cr100025t] [Citation(s) in RCA: 567] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Enzo Terreno
- Department of Chemistry IFM and Molecular Imaging Center, University of Torino, Torino, Italy
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182
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Regueiro-Figueroa M, Djanashvili K, Esteban-Gómez D, Chauvin T, Tóth E, de Blas A, Rodríguez-Blas T, Platas-Iglesias C. Molecular recognition of sialic acid by lanthanide(III) complexes through cooperative two-site binding. Inorg Chem 2010; 49:4212-23. [PMID: 20373796 DOI: 10.1021/ic902461g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Herein we report two new ligands, 1,4,7-tris(carboxymethyl)-10-[2-(dihydroxyboranyl)benzyl]-1,4,7,10-tetraazacyclododecane (L(1)) and 1,4,7-tris(carboxymethyl)-10-[3-(dihydroxyboranyl)benzyl]-1,4,7,10-tetraazacyclododecane (L(2)), which contain a phenylboronic acid (PBA) function and a 1,4,7,10-tetraazacyclododecane-1,4,7-triacetate cage for complexation of lanthanide ions in an aqueous solution. The pK(a) of the PBA function amounts to 4.6 in [Gd(L(1))] and 8.9 in [Gd(L(2))], with the value of the L(2) analogue being very similar to that of PBA (8.8). These results are explained by the coordination of the PBA function of L(1) to the Gd(III) ion, which results in a dramatic lowering of its pK(a). As a consequence, [Gd(L(1))] does not bind to saccharides at physiological pH. The nuclear magnetic relaxation dispersion profiles recorded for [Gd(L(1))] and [Gd(L(2))] confirm that the phenylboronate function is coordinated to the metal ion in the L(1) derivative, which results in a q = 0 complex. The interaction of the [Gd(L(2))] complex with 5-acetylneuraminic acid (Neu5Ac) and 2-alpha-O-methyl-5-acetylneuraminic acid (MeNeu5Ac) has been investigated by means of spectrophotometric titrations in an aqueous solution (pH 7.4, 0.1 M 3-(N-morpholino)propanesulfonic acid buffer). Furthermore, we have also investigated the binding of these receptors with competing monosaccharides such as D-(+)-glucose, D-fructose, D-mannose, D-galactose, methyl alpha-D-galactoside, and methyl alpha-D-mannoside. The binding constants obtained indicate an important selectivity of [Gd(L(2))] for Neu5Ac (K(eq) = 151) over D-(+)-glucose (K(eq) = 12.3), D-mannose (K(eq) = 21.9), and D-galactose (K(eq) = 24.5). Furthermore, a very weak binding affinity was observed in the case of methyl alpha-D-galactoside and methyl alpha-D-mannoside. An 8-fold increase of the binding constant of [Gd(L(2))] with Neu5Ac is observed when compared to that of PBA determined under the same conditions (K(eq) = 19). (13)C NMR spectroscopy and density functional theory calculations performed at the B3LYP/6-31G(d) level show that this is due to a cooperative two-site binding of Neu5Ac through (1) ester formation by interaction on the PBA function of the receptor and (2) coordination of the carboxylate group of Neu5Ac to the Gd(III) ion. The emission lifetime of the (5)D(4) level of Tb(III) in [Tb(L(2))] increases upon Neu5Ac binding, in line with the displacement of inner-sphere water molecules due to coordination of Neu5Ac to the metal ion.
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Affiliation(s)
- Martín Regueiro-Figueroa
- Departamento de Química Fundamental, Universidade da Coruña, Campus da Zapateira, Alejandro de la Sota 1, 15008 A Coruña, Spain
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183
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Fries PH, Belorizky E. Enhancement of the water proton relaxivity by trapping Gd3+ complexes in nanovesicles. J Chem Phys 2010; 133:024504. [DOI: 10.1063/1.3456987] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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184
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Huang CH, Hammell J, Ratnakar SJ, Sherry AD, Morrow JR. Activation of a PARACEST agent for MRI through selective outersphere interactions with phosphate diesters. Inorg Chem 2010; 49:5963-70. [PMID: 20509631 PMCID: PMC2893239 DOI: 10.1021/ic1004616] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ln(S-THP)(3+) complexes are paramagnetic chemical exchange saturation transfer (PARACEST) agents for magnetic resonance imaging (MRI; S-THP = (1S,4S,7S,10S)-1,4,7,10-tetrakis(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane, Ln(III) = Ce(III), Eu(III), Yb(III)). CEST spectra at 11.7 T show that the PARACEST effect of these complexes is enhanced at neutral pH in buffered solutions containing 100 mM NaCl upon the addition of 1-2 equiv of diethylphosphate (DEP). CEST images of phantoms at 4.7 T confirm that DEP enhances the properties of Yb(S-THP)(3+) as a PARACEST MRI agent in buffered solutions at neutral pH and 100 mM NaCl. Studies using (1)H NMR, direct excitation Eu(III) luminescence spectroscopy, and UV-visible spectroscopy show that DEP is an outersphere ligand. Dissociation constants for [Ln(S-THP)(OH(2))](DEP) are 1.9 mM and 2.8 mM for Ln(III) = Yb(III) at pH 7.0 and Eu(III) at pH 7.4. Related ligands including phosphorothioic acid, O,O-diethylester, ethyl methylphosphonate, O-(4-nitrophenylphosphoryl)choline, and cyclic 3,5-adenosine monophosphate do not activate PARACEST. BNPP (bis(4-nitrophenyl phosphate) activates PARACEST of Ln(S-THP)(3+) (Ln(III) = Eu(III), Yb(III)), albeit less effectively than does DEP. These data show that binding through second coordination sphere interactions is selective for phosphate diesters with two terminal oxygens and two identical ester groups. A crystal structure of [Eu(S-THP)(OH(2))]((O(2)NPhO)(2)PO(2))(2)(CF(3)SO(3)) x 2 H(2)O x iPrOH has two outersphere BNPP anions that form hydrogen bonds to the alcohol groups of the macrocycle and the bound water ligand. This structure supports (1)H NMR spectroscopy studies showing that outersphere interactions of the phosphate diester with the alcohol protons modulate the rate of alcohol proton exchange to influence the PARACEST properties of the complex. Further, DEP interacts only with the nonionized form of the complex, Ln(S-THP)(OH(2))(3+) contributing to the pH dependence of the PARACEST effect.
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Affiliation(s)
- Ching-Hui Huang
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, Fax (1)716-645-6963
| | - Jacob Hammell
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, Fax (1)716-645-6963
| | - S. James Ratnakar
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 2201 Inwood Road, Dallas, TX 75390-8568
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 2201 Inwood Road, Dallas, TX 75390-8568
- Department of Chemistry, University of Texas, Dallas, P.O. Box 830688, Richardon, TX 75083-0688, Fax (1) 972-883-2025
| | - Janet R. Morrow
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, Fax (1)716-645-6963
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185
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Frullano L, Catana C, Benner T, Sherry AD, Caravan P. Bimodal MR-PET agent for quantitative pH imaging. Angew Chem Int Ed Engl 2010; 49:2382-4. [PMID: 20191650 DOI: 10.1002/anie.201000075] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Luca Frullano
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Suite 2301, Charlestown, MA 02129, USA
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186
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Regueiro-Figueroa M, Esteban-Gómez D, de Blas A, Rodríguez-Blas T, Platas-Iglesias C. Structure and Dynamics of Lanthanide(III) Complexes with an N-Alkylated do3a Ligand (H3do3a = 1,4,7,10-Tetraazacyclododecane-1,4,7-triacetic Acid): A Combined Experimental and DFT Study. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000334] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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187
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Bonnet CS, Fries PH, Crouzy S, Delangle P. Outer-Sphere Investigation of MRI Relaxation Contrast Agents. Example of a Cyclodecapeptide Gadolinium Complex with Second-Sphere Water. J Phys Chem B 2010; 114:8770-81. [DOI: 10.1021/jp101443v] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Célia S. Bonnet
- CEA, INAC, Service de Chimie Inorganique et Biologique (UMR_E 3 CEA UJF, FRE 3200 CNRS), 38054 Grenoble, France and CEA, iRTSV, Laboratoire Chimie et Biologie des Métaux (UMR 5249 CEA CNRS UJF), F-38054 Grenoble, France
| | - Pascal H. Fries
- CEA, INAC, Service de Chimie Inorganique et Biologique (UMR_E 3 CEA UJF, FRE 3200 CNRS), 38054 Grenoble, France and CEA, iRTSV, Laboratoire Chimie et Biologie des Métaux (UMR 5249 CEA CNRS UJF), F-38054 Grenoble, France
| | - Serge Crouzy
- CEA, INAC, Service de Chimie Inorganique et Biologique (UMR_E 3 CEA UJF, FRE 3200 CNRS), 38054 Grenoble, France and CEA, iRTSV, Laboratoire Chimie et Biologie des Métaux (UMR 5249 CEA CNRS UJF), F-38054 Grenoble, France
| | - Pascale Delangle
- CEA, INAC, Service de Chimie Inorganique et Biologique (UMR_E 3 CEA UJF, FRE 3200 CNRS), 38054 Grenoble, France and CEA, iRTSV, Laboratoire Chimie et Biologie des Métaux (UMR 5249 CEA CNRS UJF), F-38054 Grenoble, France
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188
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Fries PH. Two-particle random walk simulation of outer-sphere nuclear relaxation. J Chem Phys 2010; 132:224103. [DOI: 10.1063/1.3429221] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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189
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Viswanathan S, Kovacs Z, Green KN, Ratnakar SJ, Sherry AD. Alternatives to gadolinium-based metal chelates for magnetic resonance imaging. Chem Rev 2010; 110:2960-3018. [PMID: 20397688 PMCID: PMC2874212 DOI: 10.1021/cr900284a] [Citation(s) in RCA: 313] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Subha Viswanathan
- Advanced Imaging Research Center, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 and Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
| | - Zoltan Kovacs
- Advanced Imaging Research Center, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 and Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
| | - Kayla N. Green
- Advanced Imaging Research Center, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 and Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
| | - S. James Ratnakar
- Advanced Imaging Research Center, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 and Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
| | - A. Dean Sherry
- Advanced Imaging Research Center, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390 and Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
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190
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Negri V, Cerpa A, López-Larrubia P, Nieto-Charques L, Cerdán S, Ballesteros P. Nanotubular Paramagnetic Probes as Contrast Agents for Magnetic Resonance Imaging Based on the Diffusion Tensor. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200906415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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191
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Lelyveld VS, Atanasijevic T, Jasanoff A. Challenges for Molecular Neuroimaging with MRI. INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY 2010; 20:71-79. [PMID: 20808721 PMCID: PMC2929832 DOI: 10.1002/ima.20221] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Magnetic resonance (MRI)-based molecular imaging methods are beginning to have impact in neuroscience. A growing number of molecular imaging agents have been synthesized and tested in vitro, but so far relatively few have been validated in the brains of live animals. Here, we discuss key challenges associated with expanding the repertoire of successful molecular neuroimaging approaches. The difficulty of delivering agents past the blood-brain barrier (BBB) is a particular obstacle to molecular imaging in the central nervous system. We review established and emerging techniques for trans-BBB delivery, including intracranial infusion, BBB disruption, and transporter-related methods. Improving the sensitivity with which MRI-based molecular agents can be detected is a second major challenge. Better sensitivity would in turn reduce the requirements for delivery and alleviate potential side effects. We discuss recent efforts to enhance relaxivity of conventional longitudinal relaxation time (T(1)) and transverse relaxation time (T(2)) MRI contrast agents, as well as strategies that involve amplifying molecular signals or reducing endogenous background influences. With ongoing refinement of imaging approaches and brain delivery methods, MRI-based techniques for molecular-level neuroscientific investigation will fall increasingly within reach.
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Affiliation(s)
- Victor S Lelyveld
- Department of Biological Engineering, Massachusetts Institute of Technology, NW14-2213, Cambridge, MA 02139
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Negri V, Cerpa A, López-Larrubia P, Nieto-Charques L, Cerdán S, Ballesteros P. Nanotubular Paramagnetic Probes as Contrast Agents for Magnetic Resonance Imaging Based on the Diffusion Tensor. Angew Chem Int Ed Engl 2010; 49:1813-5. [DOI: 10.1002/anie.200906415] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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193
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Abstract
In clinical practice the imaging of bone tissue is based almost exclusively on x-ray or radiochemical methods. Alternative methods, such as MRI and optical imaging, can provide not only anatomical, but also physiological information, due to their ability to reflect the properties of body fluids (temperature, pH and concentration of ions). In this article we review bone targeting probes for MRI and fluorescence imaging. As bone targeting is mainly associated with phosphonate and bisphosphonate derivatives, we also focus on their sorption behavior. Also discussed in detail is the limitation of using bone-targeting probes for MRI and optical imaging mainly due to their long-time retention in bone tissue and the low permeability of tissues for light.
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194
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Frullano L, Catana C, Benner T, Sherry A, Caravan P. Bimodal MR-PET Agent for Quantitative pH Imaging. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201000075] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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195
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Yang H, Zhang C, Shi X, Hu H, Du X, Fang Y, Ma Y, Wu H, Yang S. Water-soluble superparamagnetic manganese ferrite nanoparticles for magnetic resonance imaging. Biomaterials 2010; 31:3667-73. [PMID: 20144480 DOI: 10.1016/j.biomaterials.2010.01.055] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Accepted: 01/12/2010] [Indexed: 11/17/2022]
Abstract
We report here a thermal decomposition approach to the synthesis of water-soluble superparamagnetic manganese ferrite (MnFe(2)O(4)) nanoparticles (NPs) for magnetic resonance (MR) imaging applications. In this approach, tetraethylene glycol was utilized as a coordination and stabilization agent, rendering the NPs water-soluble and stable. The formed NPs had a diameter of 7 nm with a narrow size distribution, and were superparamagnetic with a saturated magnetization (Ms) of 39 emu/g. In vitro cytotoxicity test revealed that the MnFe(2)O(4) NPs were biocompatible at a particle concentration below 200 microg/mL. The transverse relaxivity of MnFe(2)O(4) NPs in water and cells after incubation were determined to be 189.3mm(-1)s(-1) and 36.8mm(-1)s(-1) based on iron concentration, respectively. In vivo MR imaging studies in conjunction with inductively coupled plasma-atomic emission spectroscopy showed that the MnFe(2)O(4) NPs were preferentially accumulated in liver after intravenous injection for 4h. This suggests that the developed MnFe(2)O(4) NPs can serve as a sensitive MR imaging contrast agent for liver imaging. By appropriately modifying or functionalizing the surface of the NPs, these particles may be used for MR detection of other diseases.
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Affiliation(s)
- Hong Yang
- Department of Chemistry, Shanghai Normal University, Shanghai 200234, PR China
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196
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Tallec G, Imbert D, Fries PH, Mazzanti M. Highly stable and soluble bis-aqua Gd, Nd, Yb complexes as potential bimodal MRI/NIR imaging agents. Dalton Trans 2010; 39:9490-2. [DOI: 10.1039/c0dt00994f] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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197
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Gao G, Heo H, Lee J, Lee D. An acidic pH-triggered polymeric micelle for dual-modality MR and optical imaging. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/c0jm00317d] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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198
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Hanaoka K. Development of Responsive Lanthanide-Based Magnetic Resonance Imaging and Luminescent Probes for Biological Applications. Chem Pharm Bull (Tokyo) 2010; 58:1283-94. [DOI: 10.1248/cpb.58.1283] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kenjiro Hanaoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
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Li C, Li K, Yan H, Li G, Xia J, Wei X. Dextran based pH-activated near-infrared fluorescence nanoprobe imaging the acidic compartments in cancer cells. Chem Commun (Camb) 2010; 46:1326-8. [DOI: 10.1039/b917368d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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