Dynamic Nuclear Polarization with Nitroxides Dissolved in Biological Fluids

Grucker, Daniel; Guiberteau, Thierry; Eclancher, Bernard; Chambron, J.; Chiarelli, R.; Rassat, A.; Subra, Guy; Gallez, Bernard

doi:10.1006/jmrb.1995.1019

Cited by 68 publications

(64 citation statements)

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“…The line width broadening is due to the dipolar and spin exchange interactions of agent concentrations. These results agree well with the previous studies [32][33][34][35]. The TEMPONE has a narrow line width compared with TEMPO and TEMPOL radicals.…”

Section: Line Widthsupporting

confidence: 93%

Electron Spin Resonance Spectroscopy Studies on Reduction Process of Nitroxyl Radicals used in Molecular Imaging

Dhas¹,

Jawahar²,

Benial³

2014

EJB

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Abstract:Electron spin resonance (ESR) spectroscopy studies on the reduction process of nitroxyl radicals were carried out for 1mM concentration of 14 N-labeled nitroxyl radicals in 1 mM concentration of ascorbic acid as a function of time. The half life time and decay rate were estimated for 1mM concentration of 14 N labeled nitroxyl radicals in 1 mM concentration of ascorbic acid. From the results, the increase in half life time and decrease in decay rate were calculated for TEMPONE compared with TEMPO and TEMPOL radicals, which indicates the higher stability of TEMPONE radical. The observed radical scavenging activity is also higher for TEMPONE radical. The ESR spectrum was also recorded for 1mM concentration of 14 N-labeled nitroxyl radicals in pure water and the ESR parameters, line width, hyperfine coupling constant, g-factor, signal intensity ratio and rotational correlation time were obtained. These results indicate that the TEMPONE radical has narrowest line width and fast tumbling motion compared with TEMPO and TEMPOL. Therefore, this study reveals that the TEMPONE radical can act as a good redox sensitive spin probe for molecular imaging.

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Section: Line Widthsupporting

confidence: 93%

Electron Spin Resonance Spectroscopy Studies on Reduction Process of Nitroxyl Radicals used in Molecular Imaging

Dhas¹,

Jawahar²,

Benial³

2014

EJB

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“…147 Nitroxides were also the first compounds that were tested in dynamic nuclear polarization to probe the oxygen environment. 148,149 Nitroxides have the limitation of being metabolically converted to diamagnetic hydroxylamines. However, the bioreduction is dependent on the redox state of the tissues.…”

Section: Soluble Paramagnetic Materialsmentioning

confidence: 99%

Assessment of tumor oxygenation by electron paramagnetic resonance: principles and applications

2004

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This review paper attempts to provide an overview of the principles and techniques that are often termed electron paramagnetic resonance (EPR) oximetry. The paper discusses the potential of such methods and illustrates they have been successfully applied to measure oxygen tension, an essential parameter of the tumor microenvironment. To help the reader understand the motivation for carrying out these measurements, the importance of tumor hypoxia is first discussed: the basic issues of why a tumor is hypoxic, why these hypoxic microenvironments promote processes driving malignant progression and why hypoxia dramatically influences the response of tumors to cytotoxic treatments will be explained. The different methods that have been used to estimate the oxygenation in tumors will be reviewed. To introduce the basics of EPR oximetry, the specificity of in vivo EPR will be discussed by comparing this technique with NMR and MRI. The different types of paramagnetic oxygen sensors will be presented, as well as the methods for recording the information (EPR spectroscopy, EPR imaging, dynamic nuclear polarization). Several applications of EPR for characterizing tumor oxygenation will be illustrated, with a special emphasis on pharmacological interventions that modulate the tumor microenvironment. Finally, the challenges for transposing the method into the clinic will also be discussed.

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“…Two kinds of paramagnetic materials can be used: particulate materials and soluble materials such as nitroxides or trityl radicals. [9][10][11][12] Particulate materials are usually inert and possess a higher sensitivity for oxygen than soluble materials. Once particulate materials are implanted in tissue, it is possible to make repeated localized measurements over long periods of time.…”

Section: Introductionmentioning

confidence: 99%

Development and evaluation of biocompatible inks for the local measurement of oxygen using in vivo EPR

2004

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In vivo EPR oximetry is a powerful minimally invasive method that allows the measurement of oxygen in tissues through the use of a paramagnetic probe. In the present study, we investigated new strategies for preparing biocompatible inks containing carbon black particles (Printex U), which could be used as oxygen sensors. The carbon black particles were dispersed in solutions of biocompatible polymers of carboxy methyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC) or polyvinyl pyrrolidone (PVP). A total of 12 polymers with different molecular weights were tested. A physico-chemical characterization of the inks was carried out to assess the sedimentation of the particles, the rheological behavior of these inks, and the relative diffusion of the inks. The preparations with CMC and PVP had the highest viscosity and stability. The presence of the polymers did not modify the calibration curves (EPR linewidth as a function of the pO 2 ) of the carbon black. In vivo, the oxygen sensors were stable for at least one month in muscles as the EPR linewidth remained fully sensitive to induced ischemia or carbogen challenge. The calibration curve was not modified after this period of implantation. A first study of biocompatibility was carried out in vitro (hemolysis and cytotoxicity assay) and in vivo (histological examination). No sign of toxicity was observed using these inks. These preparations are good candidates for future in vivo studies including clinical trials.

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Dynamic Nuclear Polarization with Nitroxides Dissolved in Biological Fluids

Cited by 68 publications

References 0 publications

Electron Spin Resonance Spectroscopy Studies on Reduction Process of Nitroxyl Radicals used in Molecular Imaging

Electron Spin Resonance Spectroscopy Studies on Reduction Process of Nitroxyl Radicals used in Molecular Imaging

Assessment of tumor oxygenation by electron paramagnetic resonance: principles and applications

Development and evaluation of biocompatible inks for the local measurement of oxygen using in vivo EPR

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