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55. EPR Image Based Oxygen Movies for Transient Hypoxia

Author

Redler, Gage, Epel, Boris, Halpern, Howard J., Cohen, Irun R., Series Editor, Lajtha, Abel, Series Editor, Paoletti, Rodolfo, Series Editor, Lambris, John D., Series Editor, Swartz, Harold M., editor, Harrison, David K., editor, and Bruley, Duane F., editor

Published
2014
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56. What We Learn from In Vivo EPR Oxygen Images

Author

Redler, Gage, Epel, Boris, Halpern, Howard J., Cohen, Irun R., Series Editor, Lajtha, Abel, Series Editor, Paoletti, Rodolfo, Series Editor, Lambris, John D., Series Editor, Swartz, Harold M., editor, Harrison, David K., editor, and Bruley, Duane F., editor

Published
2014
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57. How In Vivo EPR Measures and Images Oxygen

Author

Epel, Boris, Redler, Gage, Halpern, Howard J., Cohen, Irun R., Series Editor, Lajtha, Abel, Series Editor, Paoletti, Rodolfo, Series Editor, Lambris, John D., Series Editor, Swartz, Harold M., editor, Harrison, David K., editor, and Bruley, Duane F., editor

Published
2014
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70. The optimal 18F-Fluoromisonidazole PET threshold to define tumor hypoxia in preclinical squamous cell carcinomas using pO2 electron paramagnetic resonance imaging as reference truth.

Author

Gertsenshteyn, Inna, primary, Epel, Boris, additional, Ahluwalia, Amandeep, additional, Kim, Heejong, additional, Fan, Xiaobing, additional, Barth, Eugene, additional, Zamora, Marta, additional, Markiewicz, Erica, additional, Tsai, Hsui-Ming, additional, Sundramoorthy, Subramanian, additional, Leoni, Lara, additional, Lukens, John, additional, Bhuiyan, Mohammed, additional, Freifelder, Richard, additional, Kucharski, Anna, additional, Giurcanu, Mihai, additional, Roman, Brian, additional, Karczmar, Gregory, additional, Kao, Chien-Min, additional, Halpern, Howard, additional, and Chen, Chin-Tu, additional

Published
2022
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76. The optimal 18F-fluoromisonidazole PET threshold to define tumor hypoxia in preclinical squamous cell carcinomas using pO2 electron paramagnetic resonance imaging as reference truth.

Author

Gertsenshteyn, Inna, Epel, Boris, Ahluwalia, Amandeep, Kim, Heejong, Fan, Xiaobing, Barth, Eugene, Zamora, Marta, Markiewicz, Erica, Tsai, Hsiu-Ming, Sundramoorthy, Subramanian, Leoni, Lara, Lukens, John, Bhuiyan, Mohammed, Freifelder, Richard, Kucharski, Anna, Giurcanu, Mihai, Roman, Brian B., Karczmar, Gregory, Kao, Chien-Min, and Halpern, Howard

Subjects
*HYPOXEMIA, *TUMOR treatment, *POSITRON emission tomography, *SQUAMOUS cell carcinoma, *RECEIVER operating characteristic curves
Abstract

Purpose: To identify the optimal threshold in 18F-fluoromisonidazole (FMISO) PET images to accurately locate tumor hypoxia by using electron paramagnetic resonance imaging (pO2 EPRI) as ground truth for hypoxia, defined by pO2 ≤ 10 mmHg. Methods: Tumor hypoxia images in mouse models of SCCVII squamous cell carcinoma (n = 16) were acquired in a hybrid PET/EPRI imaging system 2 h post-injection of FMISO. T2-weighted MRI was used to delineate tumor and muscle tissue. Dynamic contrast enhanced (DCE) MRI parametric images of Ktrans and ve were generated to model tumor vascular properties. Images from PET/EPR/MRI were co-registered and resampled to isotropic 0.5 mm voxel resolution for analysis. PET images were converted to standardized uptake value (SUV) and tumor-to-muscle ratio (TMR) units. FMISO uptake thresholds were evaluated using receiver operating characteristic (ROC) curve analysis to find the optimal FMISO threshold and unit with maximum overall hypoxia similarity (OHS) with pO2 EPRI, where OHS = 1 shows perfect overlap and OHS = 0 shows no overlap. The means of dice similarity coefficient, normalized Hausdorff distance, and accuracy were used to define the OHS. Monotonic relationships between EPRI/PET/DCE-MRI were evaluated with the Spearman correlation coefficient (ρ ) to quantify association of vasculature on hypoxia imaged with both FMISO PET and pO2 EPRI. Results: FMISO PET thresholds to define hypoxia with maximum OHS (both OHS = 0.728 ± 0.2) were SUV ≥ 1.4 × SUVmean and SUV ≥ 0.6 × SUVmax. Weak-to-moderate correlations (| ρ |< 0.70) were observed between PET/EPRI hypoxia images with vascular permeability (Ktrans) or fractional extracellular-extravascular space (ve) from DCE-MRI. Conclusion: This is the first in vivo comparison of FMISO uptake with pO2 EPRI to identify the optimal FMISO threshold to define tumor hypoxia, which may successfully direct hypoxic tumor boosts in patients, thereby enhancing tumor control. [ABSTRACT FROM AUTHOR]

Published
2022
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78. Highly sensitive electron paramagnetic resonance nanoradicals for quantitative intracellular tumor oxymetric images

Author

Chen,Nai-Tzu, Barth,Eugene D., Lee,Tsung-Hsi, Chen,Chin-Tu, Epel,Boris, Halpern,Howard, and Lo,Leu-Wei

Subjects
Male, Free Radicals, Electron Spin Resonance Spectroscopy, Mice, Nude, Silicon Dioxide, tumor oxygenation, Fluorescence, Oxygen, triarylmethyl (trityl) spin probe, Imaging, Three-Dimensional, Oxygen Consumption, International Journal of Nanomedicine, mesoporous silica nanoparticles (MSNs), Cell Line, Tumor, Neoplasms, Animals, Humans, Nanoparticles, electron paramagnetic resonance imaging (EPRI), Oximetry, Porosity, Original Research
Abstract

Nai-Tzu Chen,1 Eugene D Barth,2,3 Tsung-Hsi Lee,4 Chin-Tu Chen,5 Boris Epel,2,3 Howard J Halpern,2,3 Leu-Wei Lo5,61Institute of New Drug Development, China Medical University, Taichung 40402, Taiwan; 2Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA; 3Center for EPR Imaging In Vivo Physiology, University of Chicago, Chicago, IL 60637, USA; 4Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan; 5Department of Radiology, University of Chicago, Chicago, IL 60637 USA; 6Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Zhunan 35053, TaiwanPurpose: Tumor oxygenation is a critical parameter influencing the efficacy of cancer therapy. Low levels of oxygen in solid tumor have been recognized as an indicator of malignant progression and metastasis, as well as poor response to chemo- and radiation therapy. Being able to measure oxygenation for an individual’s tumor would provide doctors with a valuable way of identifying optimal treatments for patients.Methods: Electron paramagnetic resonance imaging (EPRI) in combination with an oxygen-measuring paramagnetic probe was performed to measure tumor oxygenation in vivo. Triarylmethyl (trityl) radical exhibits high specificity, sensitivity, and resolution for quantitative measurement of O2 concentration. However, its in vivo applications in previous studies have been limited by the required high dosage, its short half-life, and poor intracellular permeability. To address these limitations, we developed high-capacity nanoformulated radicals that employed fluorescein isothiocyanate-labeled mesoporous silica nanoparticles (FMSNs) as trityl radical carriers. The high surface area nanostructure and easy surface modification of physiochemical properties of FMSNs enable efficient targeted delivery of highly concentrated, nonself-quenched trityl radicals, protected from environmental degradation and dilution.Results: We successfully designed and synthesized a tumor-targeted nanoplatform as a carrier for trityl. In addition, the nanoformulated trityl does not affect oxygen-sensing capacity by a self-relaxation or broadening effect. The FMSN-trityl exhibited high sensitivity/response to oxygen in the partial oxygen pressure range from 0 to 155 mmHg. Furthermore, MSN-trityl displayed outstanding intracellular oxygen mapping in both in vitro and in vivo animal studies.Conclusion: The highly sensitive nanoformulated trityl spin probe can profile intracellular oxygen distributions of tumor in a real-time and quantitative manner using in vivo EPRI.Keywords: tumor oxygenation, electron paramagnetic resonance imaging (EPRI), mesoporous silica nanoparticles (MSNs), triarylmethyl (trityl) spin probe

Published
2019

81. An inverse-breathing encapsulation system for cell delivery

Author

Wang, Long-Hai, primary, Ernst, Alexander Ulrich, additional, Flanders, James Arthur, additional, Liu, Wanjun, additional, Wang, Xi, additional, Datta, Ashim K., additional, Epel, Boris, additional, Kotecha, Mrignayani, additional, Papas, Klearchos K., additional, and Ma, Minglin, additional

Published
2021
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88. Improving Tumor Hypoxia Location in 18F-Misonidazole PET with Dynamic Contrast-enhanced MRI Using Quantitative Electron Paramagnetic Resonance Partial Oxygen Pressure Images

Author

Gertsenshteyn, Inna, primary, Epel, Boris, additional, Barth, Eugene, additional, Leoni, Lara, additional, Markiewicz, Erica, additional, Tsai, Hsiu-Ming, additional, Fan, Xiaobing, additional, Giurcanu, Mihai, additional, Bodero, Darwin, additional, Zamora, Marta, additional, Sundramoorthy, Subramanian, additional, Kim, Heejong, additional, Freifelder, Richard, additional, Bhuiyan, Mohammed, additional, Kucharski, Anna, additional, Karczmar, Gregory, additional, Kao, Chien-Min, additional, Halpern, Howard, additional, and Chen, Chin-Tu, additional

Published
2021
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89. Electronic structure of the [Mn.sub.4][O.sub.x]Ca cluster in the [S.sub.0] and [S.sub.2] states of the oxygen-evolving complex of photosystem II based on pulse [super 55]Mn-ENDOR and EPR spectroscopy

Author

Kulik, Leonid V., Epel, Boris, Lubitz, Wolfgang, and Messinger, Johannes

Subjects
Photosystem II -- Research, Electron paramagnetic resonance spectroscopy -- Usage, Chemistry
Abstract

The overall manganese oxidization states of the oxygen-evolving complex (OEC) in the [S.sub.0] and [S.sub.2] states are determined for methanol containing spinach photosystem II (PSII) membrane fragments. The analysis has shown that the [Mn.sub.4][O.sub.x]Ca cluster has taken part in the unique water splitting chemistry through the structural changes, of which one can be located within the cluster.

Published
2007

95. Axial solvent coordination in oBase-offo Cob(II)alamin and related Co(II)-corrinates revealed by 2D-EPR

Author

Doorslaer, Sabine Van, Jeschke, Gunnar, Epel, Boris, Goldfarb, Daniella, Schweiger, Arthur, and Eichel, Rudiger-Albert

Subjects
Cobalt -- Research, Cobalt -- Magnetic properties, Electron paramagnetic resonance -- Usage, Chemistry
Abstract

Electron paramagnetic resonance (EPR) study on Co(II)corrins Cob(II)ester(1+) and base-off B12r(2+) provides the first direct evidence for axial solvent ligation in polar solvents. EPR forms an excellent tool to analyze subtle changes in the electronic structure of Co(super II)-corrin systems, especially when they are supported by density functional computations.

Published
2003

97. Abstract 2773: Increased tumor control boosting hypoxic regions identified with EPR pO2 imaging in 2 tumor types

Author

Halpern, Howard, primary, Maggio, Matthew, additional, Barth, Eugene, additional, Bodero, Darwin, additional, Miller, Richard C., additional, Pelizzari, Charles A., additional, Krzykawska-Serda, Martyna, additional, Sundramoorthy, Subramanian V., additional, Aydogan, Bulent, additional, Weichselbaum, Ralph R., additional, Tormyshev, Victor M., additional, Gertsenshteyn, Inna, additional, and Epel, Boris, additional

Published
2020
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98. Abstract 1648: Multimodal imaging of tumor hypoxia with 18F-misonidazole PET, EPR, and MRI

Author

Gertsenshteyn, Inna, primary, Epel, Boris, additional, Leoni, Lara, additional, Fan, Xiaobing, additional, Friefelder, Richard, additional, Barth, Eugene, additional, Kim, Heejong, additional, Zamora, Marta, additional, Markiewicz, Erica, additional, Bodero, Darwin, additional, Bhuiyan, Mohammed, additional, Kucharski, Anna, additional, Tsai, Hsiu-Ming, additional, Grana, Mellissa, additional, Sundramoorthy, Subramanian V., additional, Karczmar, Gregory S., additional, Kao, Chien-Min, additional, Chen, Chin-Tu, additional, and Halpern, Howard, additional

Published
2020
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