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Almog N, Zgadzai O, Kuppusamy P, Zur Y, Baruch L, Machluf M, Blank A. Hand-held electron spin resonance scanner for subcutaneous oximetry using OxyChip. Magn Reson Med 2024; 92:430-439. [PMID: 38411265 PMCID: PMC11055674 DOI: 10.1002/mrm.30066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/28/2024]
Abstract
PURPOSE Electron spin resonance (ESR) is used to measure oxygen partial pressure (pO2) in biological media with many clinical applications. Traditional clinical ESR involves large magnets that encompass the subject of measurement. However, certain applications might benefit from a scanner operating within local static magnetic fields. Our group recently developed such a compact scanner for transcutaneous (surface) pO2 measurements of skin tissue. Here we extend this capability to subsurface (subcutaneous) pO2 measurements and verify it using an artificial tissue emulating (ATE) phantom. METHODS We introduce a new scanner, tailored for subcutaneous measurements up to 2 mm beneath the skin's surface. This scanner captures pulsed ESR signals from embedded approximate 1-mm oxygen-sensing solid paramagnetic implant, OxyChip. The scanner features a static magnetic field source, producing a uniform region outside its surface, and a compact microwave resonator, for exciting and receiving ESR signals. RESULTS ESR readings derived from an OxyChip, positioned approximately 1.5 mm from the scanner's surface, embedded in ATE phantom, exhibited a linear relation of 1/T2 versus pO2 for pO2 levels at 0, 7.6, 30, and 160 mmHg, with relative reading accuracy of about 10%. CONCLUSION The compact ESR scanner can report pO2 data in ATE phantom from an external position relative to the scanner. Implementing this scanner in preclinical and clinical applications for subcutaneous pO2 measurements is a feasible next phase for this development. This innovative design also has the potential to operate in conjunction with artificial skin graft for wound healing, combining therapeutic and pO2 diagnostic features.
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Affiliation(s)
- Nir Almog
- Schulich Faculty of Chemistry, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Oleg Zgadzai
- Schulich Faculty of Chemistry, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Periannan Kuppusamy
- Departments of Radiology, Radiation Oncology, and Medicine, Geisel School of Medicine, Dartmouth College, Lebanon, NH 03756, USA
| | - Yehonatan Zur
- Faculty of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Limor Baruch
- Faculty of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Marcelle Machluf
- Faculty of Biotechnology and Food Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion – Israel Institute of Technology, Haifa 32000, Israel
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Szczygieł M, Kalinowska B, Szczygieł D, Krzykawska-Serda M, Fiedor L, Murzyn AA, Sopel J, Matuszak Z, Elas M. EPR Monitoring of Oxygenation Levels in Tumors After Chlorophyllide-Based Photodynamic Therapy May Allow for Early Prediction of Treatment Outcome. Mol Imaging Biol 2024:10.1007/s11307-023-01886-7. [PMID: 38296885 DOI: 10.1007/s11307-023-01886-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 02/02/2024]
Abstract
PURPOSE Molecular oxygen, besides a photosensitizer and light of appropriate wavelength, is one of the three factors necessary for photodynamic therapy (PDT). In tumor tissue, PDT leads to the killing of tumor cells, destruction of endothelial cells and vasculature collapse, and the induction of strong immune responses. All these effects may influence the oxygenation levels, but it is the vasculature changes that have the main impact on pO2. The purpose of our study was to monitor changes in tumor oxygenation after PDT and explore its significance for predicting long-term treatment response. PROCEDURES Electron paramagnetic resonance (EPR) spectroscopy enables direct, quantitative, and sequential measurements of partial pressure of oxygen (pO2) in the same animal. The levels of chlorophyll derived photosensitizers in tumor tissue were determined by transdermal emission measurements. RESULTS The noninvasive monitoring of pO2 in the tumor tissue after PDT showed that the higher ΔpO2 (pO2 after PDT minus pO2 before PDT), the greater the inhibition of tumor growth. ΔpO2 also correlated with higher levels of the photosensitizers in the tumor and with the occurrence of a severe edema/erythema after PDT. CONCLUSION Monitoring of PDT-induced changes in tumor oxygenation is a valuable prognostic factor and could be also used to identify potentially resistant tumors, which is important in predicting long-term treatment response.
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Affiliation(s)
- Małgorzata Szczygieł
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
| | - Barbara Kalinowska
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Dariusz Szczygieł
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | | | - Leszek Fiedor
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Aleksandra Anna Murzyn
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Doctoral School of Exact and Natural Sciences, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Justyna Sopel
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
- Doctoral School of Exact and Natural Sciences, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Zenon Matuszak
- Department of Biophysics and Medical Physics, Faculty of Physics and Computer Science, AGH University of Science and Technology, Krakow, Poland
| | - Martyna Elas
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
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Sojka A, Price BD, Sherwin MS. Order-of-magnitude SNR improvement for high-field EPR spectrometers via 3D printed quasi-optical sample holders. SCIENCE ADVANCES 2023; 9:eadi7412. [PMID: 37729398 PMCID: PMC10511183 DOI: 10.1126/sciadv.adi7412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/18/2023] [Indexed: 09/22/2023]
Abstract
Here, we present a rapidly prototyped, cost-efficient, and 3D printed quasi-optical sample holder for improving the signal-to-noise ratio (SNR) in modern, resonator-free, and high-field electron paramagnetic resonance (HFEPR) spectrometers. Such spectrometers typically operate in induction mode: The detected EPR ("cross-polar") signal is polarized orthogonal to the incident ("co-polar") radiation. The sample holder makes use of an adjustable sample positioner that allows for optimizing the sample position to maximize the 240-gigahertz magnetic field B1 and a rooftop mirror that allows for small rotations of the microwave polarization to maximize the cross-polar signal and minimize the co-polar background. When optimally tuned, the sample holder was able to improve co-polar isolation by ≳20 decibels, which is proven beneficial for maximizing the SNR in rapid-scan, pulsed, and continuous-wave EPR experiments. In rapid-scan mode, the improved SNR enabled the recording of entire EPR spectra of a narrow-line radical in millisecond time scales, which, in turn, enabled real-time monitoring of a sample's evolving line shape.
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Affiliation(s)
- Antonín Sojka
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, USA
- Institute for Terahertz Science and Technology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Brad D. Price
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, USA
- Institute for Terahertz Science and Technology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Mark S. Sherwin
- Department of Physics, University of California, Santa Barbara, Santa Barbara, CA, USA
- Institute for Terahertz Science and Technology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
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Matsumoto KI, Ueno M, Shoji Y, Nakanishi I. Estimation of the Local Concentration of the Markedly Dense Hydroxyl Radical Generation Induced by X-rays in Water. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030592. [PMID: 35163857 PMCID: PMC8840408 DOI: 10.3390/molecules27030592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 11/16/2022]
Abstract
The linear-density (number of molecules on an arbitrary distance) of X-ray-induced markedly dense hydroxyl radicals (•OH) in water was estimated based on EPR spin-trapping measurement. A lower (0.13 mM-2.3 M) concentration series of DMPO water solutions and higher (1.7-6.0 M) concentration series of DMPO water solutions plus neat DMPO liquid (8.8 M as DMPO) were irradiated with 32 Gy of X-rays. Then, the yield of DMPO-OH in DMPO water solutions and the total spin-adduct of DMPO in neat DMPO were quantified. For the higher concentration DMPO series, the EPR peak area was estimated by double integration, and the baseline correction of the integral spectrum is necessary for accurate estimation of the peak area. The preparation of a suitable standard sample corresponding to the electric permittivity according to DMPO concentration was quite important for quantification of DMPO-OH, especially in DMPO concentration beyond 2 M. The linear-density of •OH generation in water by X-ray irradiation was estimated from the inflection point on the plot of the DMPO-OH yield versus DMPO linear-density. The linear-density of X-ray-induced markedly dense •OH was estimated as 1168 μm-1, which was converted to 0.86 nm as the intermolecular distance and 2.6 M as the local concentration.
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Affiliation(s)
- Ken-ichiro Matsumoto
- Quantitative RedOx Sensing Group, Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555, Chiba, Japan; (M.U.); (Y.S.)
- Correspondence: ; Tel.: +81-43-206-3123
| | - Megumi Ueno
- Quantitative RedOx Sensing Group, Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555, Chiba, Japan; (M.U.); (Y.S.)
| | - Yoshimi Shoji
- Quantitative RedOx Sensing Group, Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555, Chiba, Japan; (M.U.); (Y.S.)
- Quantum RedOx Chemistry Group, Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555, Chiba, Japan;
| | - Ikuo Nakanishi
- Quantum RedOx Chemistry Group, Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555, Chiba, Japan;
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Cristea D, Wolfson H, Ahmad R, Twig Y, Kuppusamy P, Blank A. Compact electron spin resonance skin oximeter: Properties and initial clinical results. Magn Reson Med 2020; 85:2915-2925. [PMID: 33210362 DOI: 10.1002/mrm.28595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/22/2020] [Accepted: 10/22/2020] [Indexed: 01/22/2023]
Abstract
PURPOSE Skin oxygen level is of significance for the diagnosis and treatment of many clinical problems, such as chronic wounds and diabetic foot ulcers. Furthermore, skin oxygen levels can be correlated to arterial oxygen partial pressure, thereby revealing potentially dangerous conditions such as hyperoxia (too much oxygen), which may occur in ventilated neonates. Traditionally, skin oxygen levels are measured using electrochemical methods and, more recently, also by fluorescence lifetime techniques. These approaches suffer from several drawbacks, rendering them suboptimal. The purpose of this work is to develop an electron spin resonance (ESR) -based method for monitoring oxygen partial pressure (pO2 ) in skin tissue. METHODS A compact sensor for pulsed ESR is designed and constructed. Our ESR-based method makes use of a unique exogenous paramagnetic spin probe that is placed on the skin in a special partially sealed sticker, and subsequently measuring its signal with the compact pulsed ESR sensor that includes a miniature magnet and a small S-band (~2.3 GHz) microwave resonator. The inverse of the spin-spin relaxation time (1/T2 ) measured by ESR is shown to be linearly correlated with pO2 levels. RESULTS The sensor and its matching sticker were tested both in vitro and in vivo (with human subjects). Measured skin pO2 levels reached equilibrium after ~2-3 h and were found to be comparable to those measured by continuous-wave (CW) ESR using a large electromagnet. CONCLUSIONS A compact pulsed ESR sensor with a matching paramagnetic sticker can be used for pO2 monitoring of the skin tissue, similar to large bulky CW ESR systems.
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Affiliation(s)
- David Cristea
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Helen Wolfson
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rizwan Ahmad
- Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Ygal Twig
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Periannan Kuppusamy
- Departments of Radiology and Medicine, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire, USA
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
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Pursley R, Enomoto A, Wu H, Brender JR, Pohida T, Subramanian S, Krishna MC, Devasahayam N. Towards reduction of SAR in scaling up in vivo pulsed EPR imaging to larger objects. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 299:42-48. [PMID: 30579225 PMCID: PMC6753525 DOI: 10.1016/j.jmr.2018.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 12/10/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
An excessive RF power requirement is one of the main obstacles in the clinical translation of EPR imaging. The radio frequency (RF) pulses used in EPR imaging to excite electron spins must be very short to match their fast relaxation. With traditional pulse schemes and ninety degree flip angles, this can lead to either unsafe specific absorption rate (SAR) levels or unfeasibly long repetition times. In spectroscopy experiments, it has been shown that stochastic excitation and correlation detection can reduce the power while maintaining sensitivity but have yet to be applied to imaging experiments. Stochastic excitation is implemented using a pseudo-random phase modulation of the input stimulus. Using a crossed coil resonator assembly comprised of an outer saddle coil and an inner surface coil, it was possible to obtain a minimum isolation of ∼50 dB across a 12 MHz bandwidth. An incident peak RF power of 5 mW was used to excite the system. The low background signal obtained from this resonator allowed us to generate images with 32 dB (>1000:1) signal-to-noise ratio (SNR) while exciting with a traditional pulse sequence in a phantom containing the solid paramagnetic probe NMP-TCNQ (N-methyl pyridinium tetracyanoquinodimethane). Using two different stochastic excitation schemes, we were able to achieve a greater than 4-fold increase in SNR at the same peak power and number of averages, compared to single pulse excitation. This procedure allowed imaging at significantly lower RF power levels than used in conventional EPR imaging system configurations. Similar techniques may enable clinical applications for EPR imaging by facilitating the use of larger RF coils while maintaining a safe SAR level.
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Affiliation(s)
- Randall Pursley
- Signal Processing and Instrumentation Section, Computational Bioscience and Engineering Laboratory, Office of Intramural Research, National Institutes of Health, Bethesda, MD 20892, United States.
| | - Ayano Enomoto
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States; Department of Biophysical Chemistry, Nagasaki International University, Japan
| | - Haitao Wu
- Image Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Jeffrey R Brender
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Thomas Pohida
- Signal Processing and Instrumentation Section, Computational Bioscience and Engineering Laboratory, Office of Intramural Research, National Institutes of Health, Bethesda, MD 20892, United States
| | - Sankaran Subramanian
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States; Indian Institute of Technology, Madras, Chennai, India
| | - Murali C Krishna
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Nallathamby Devasahayam
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
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Enomoto A, Qian C, Devasahayam N, Kishimoto S, Oshima N, Blackman B, Swenson RE, Mitchell JB, Koretsky AP, Krishna MC. Wireless implantable coil with parametric amplification for in vivo electron paramagnetic resonance oximetric applications. Magn Reson Med 2018; 80:2288-2298. [PMID: 29603378 DOI: 10.1002/mrm.27185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/23/2018] [Accepted: 02/28/2018] [Indexed: 11/06/2022]
Abstract
PURPOSE To develop an implantable wireless coil with parametric amplification capabilities for time-domain electron paramagnetic resonance (EPR) spectroscopy operating at 300 MHz. METHODS The wireless coil and lithium phthalocyanine (LiPc), a solid paramagnetic probe, were each embedded individually in a biocompatible polymer polydimethoxysiloxane (PDMS). EPR signals from the LiPc embedded in PDMS (LiPc/PDMS) were generated by a transmit-receive surface coil tuned to 300 MHz. Parametric amplification was configured with an external pumping coil tuned to 600 MHz and placed between the surface coil resonator and the wireless coil. RESULTS Phantom studies showed significant enhancement in signal to noise using the pumping coil. However, no influence of the pumping coil on the oxygen-dependent EPR spectral linewidth of LiPc/PDMS was observed, suggesting the validity of parametric amplification of EPR signals for oximetry by implantation of the encapsulated wireless coil and LiPc/PDMS in deep regions of live objects. In vivo studies demonstrate the feasibility of this approach to longitudinally monitor tissue pO2 in vivo and also monitor acute changes in response to pharmacologic challenges. The encapsulated wireless coil and LiPc/PDMS engendered no host immune response when implanted for ∼3 weeks and were found to be well tolerated. CONCLUSIONS This approach may find applications for monitoring tissue oxygenation to better understand the pathophysiology associated with wound healing, organ transplantation, and ischemic diseases.
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Affiliation(s)
- Ayano Enomoto
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Chunqi Qian
- Laboratory of Functional and Molecular Imaging, NINDS, NIH, Bethesda, Maryland.,Department of Radiology, Michigan State University, East Lansing, Michigan
| | | | - Shun Kishimoto
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Nobu Oshima
- Urologic Oncology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | | | - Rolf E Swenson
- Image Probe Development Center, NHLBI, NIH, Bethesda, Maryland
| | - James B Mitchell
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Alan P Koretsky
- Laboratory of Functional and Molecular Imaging, NINDS, NIH, Bethesda, Maryland
| | - Murali C Krishna
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
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Khan N, Hou H, Swartz HM, Kuppusamy P. Direct and Repeated Measurement of Heart and Brain Oxygenation Using In Vivo EPR Oximetry. Methods Enzymol 2015; 564:529-52. [PMID: 26477264 DOI: 10.1016/bs.mie.2015.06.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Low level of oxygen (hypoxia) is a critical factor that defines the pathological consequence of several pathophysiologies, particularly ischemia, that usually occur following the blockage of a blood vessel in vital organs, such as brain and heart, or abnormalities in the microvasculature, such as peripheral vascular disease. Therefore, methods that can directly and repeatedly quantify oxygen levels in the brain and heart will significantly improve our understanding of ischemic pathologies. Importantly, such oximetry capability will facilitate the development of strategies to counteract low levels of oxygen and thereby improve outcome following stroke or myocardial infarction. In vivo electron paramagnetic resonance (EPR) oximetry has the capability to monitor tissue oxygen levels in real time. The method has largely been tested and used in experimental animals, although some clinical measurements have been performed. In this chapter, a brief overview of the methodology to repeatedly quantify oxygen levels in the brain and heart of experimental animal models, ranging from mice to swine, is presented. EPR oximetry requires a one-time placement of an oxygen-sensitive probe in the tissue of interest, while the rest of the procedure for reliable, accurate, and repeated measurements of pO2 (partial pressure of oxygen) is noninvasive and can be repeated as often as desired. A multisite oximetry approach can be used to monitor pO2 at many sites simultaneously. Building on significant advances in the application of EPR oximetry in experimental animal models, spectrometers have been developed for use in human subjects. Initial feasibility of pO2 measurement in solid tumors of patients has been successfully demonstrated.
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Affiliation(s)
- Nadeem Khan
- Department of Radiology, EPR Center for the Study of Viable Systems, Geisel School of Medicine at Dartmouth, Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Huagang Hou
- Department of Radiology, EPR Center for the Study of Viable Systems, Geisel School of Medicine at Dartmouth, Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Harold M Swartz
- Department of Radiology, EPR Center for the Study of Viable Systems, Geisel School of Medicine at Dartmouth, Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Periannan Kuppusamy
- Department of Radiology, EPR Center for the Study of Viable Systems, Geisel School of Medicine at Dartmouth, Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
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Wiernek BK, Pilawa B, Zdybel M, Buszman E, Wrześniok D. Interaction of free radicals of DOPA-melanin-streptomycin complexes with paramagnetic oxygen O 2. J Appl Biomed 2014. [DOI: 10.1016/j.jab.2013.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Zdybel M, Pilawa B, Buszman E, Wrześniok D. Effect of oxygen on free radicals in DOPA–melanin complexes with netilmicin, diamagnetic Zn(II), and paramagnetic Cu(II). Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Zhao L, Qi D, Zhang L, Bai M, Cai X. Electronic structures, spectroscopic properties, and reaction activities of porphyrins with alkali metal ions: density functional theory approach to the central metal effects. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424612501039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Density functional theory (DFT) calculation method was employed to investigate a series of nine alkali metal porphyrins (alk-Pors), namely HLiPor , HNaPor , HKPor , Li2Por , LiNaPor , LiKPor , Na2Por , NaKPor , and K2Por . These molecules show different configurations depending on different metal ions which locate over the central hole of the porphyrin ligand. Alk-Pors with larger-radius metal ion have smaller binding energy and thus is more difficult to keep stable. Further detailed molecular stability analysis was carried out by noncovalent interaction and electrostatic interaction via RDG and NBO charge distribution. UV-vis spectra of these nine compounds also show different spectral shapes depending on the central metals, and the dominant state transitions with high degeneracy are revealed to be influenced by high molecular symmetric order. Finally their difference in reactivity due to the electronegativity of central metals and the nature of porphyrin rings are predicted by electrostatic potential and Fukui functions.
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Affiliation(s)
- Luyang Zhao
- Marine College, Shandong University at Weihai, Weihai 264209, China
- Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Dongdong Qi
- Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Lijuan Zhang
- Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Ming Bai
- Marine College, Shandong University at Weihai, Weihai 264209, China
- Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Xue Cai
- Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
- Department of Chemistry, Mudanjiang Normal College, Mudanjiang 157012, China
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Angelos MG, Yeh ST, Aune SE. Post-cardiac arrest hyperoxia and mitochondrial function. Resuscitation 2011; 82 Suppl 2:S48-51. [DOI: 10.1016/s0300-9572(11)70151-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Müller BAL, Dhalla NS. Mechanisms of the beneficial actions of ischemic preconditioning on subcellular remodeling in ischemic-reperfused heart. Curr Cardiol Rev 2011; 6:255-64. [PMID: 22043201 PMCID: PMC3083806 DOI: 10.2174/157340310793566118] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 09/03/2010] [Accepted: 09/15/2010] [Indexed: 12/17/2022] Open
Abstract
Cardiac function is compromised by oxidative stress which occurs upon exposing the heart to ischemia reperfusion (I/R) for a prolonged period. The reactive oxygen species (ROS) that are generated during I/R incur extensive damage to the myocardium and result in subcellular organelle remodeling. The cardiac nucleus, glycocalyx, myofilaments, sarcoplasmic reticulum, sarcolemma, and mitochondria are affected by ROS during I/R injury. On the other hand, brief periods of ischemia followed by reperfusion, or ischemic preconditioning (IPC), have been shown to be cardioprotective against oxidative stress by attenuating the cellular damage and alterations of subcellular organelles caused by subsequent I/R injury. Endogenous defense mechanisms, such as antioxidant enzymes and heat shock proteins, are activated by IPC and thus prevent damage caused by oxidative stress. Although these cardioprotective effects of IPC against I/R injury are considered to be a consequence of changes in the redox state of cardiomyocytes, IPC is considered to promote the production of NO which may protect subcellular organelles from the deleterious actions of oxidative stress. The article is intended to focus on the I/R-induced oxidative damage to subcellular organelles and to highlight the cardioprotective effects of IPC. In addition, the actions of various endogenous cardioprotective interventions are discussed to illustrate that changes in the redox state due to IPC are cardioprotective against I/R injury to the heart.
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Affiliation(s)
- By Alison L Müller
- Institute of Cardiovascular Sciences, St Boniface Hospital Research Centre, and Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada R2H 2A6
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HOU H, DONG R, LARIVIERE JP, MUPPARAJU SP, SWARTZ HM, KHAN N. Synergistic combination of hyperoxygenation and radiotherapy by repeated assessments of tumor pO2 with EPR oximetry. JOURNAL OF RADIATION RESEARCH 2011; 52:568-74. [PMID: 21799293 PMCID: PMC3955714 DOI: 10.1269/jrr.11028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The effect of hyperoxygenation with carbogen (95% O(2) + 5% CO(2)) inhalation on RIF-1 tumor pO(2 )and its consequence on growth inhibition with fractionated radiotherapy is reported. The temporal changes in the tumor pO(2) were assessed by in vivo Electron Paramagnetic Resonance (EPR) oximetry in mice breathing 30% O(2) or carbogen and the tumors were irradiated with 4 Gy/day for 5 consecutive days; a protocol that emulates the clinical application of carbogen. The RIF-1 tumors were hypoxic with a tissue pO(2) of 5-9 mmHg. Carbogen (CB) breathing significantly increased tumor pO(2), with a maximum increase at 22.9-31.2 min on days 1-5, however, the magnitude of increase in pO(2) declined on day 5. Radiotherapy during carbogen inhalation (CB/RT) resulted in a significant tumor growth inhibition from day 3 to day 6 as compared to 30%O(2)/RT and carbogen (CB/Sham RT) groups. The results provide unambiguous quantitative information on the effect of carbogen inhalation on tumor pO(2) over the course of 5 days. Tumor growth inhibition in the CB/RT group confirms that the tumor oxygenation with carbogen was radiobiologically significant. Repeated tumor pO(2) measurements by EPR oximetry can provide temporal information that could be used to improve therapeutic outcomes by scheduling doses at times of improved tumor oxygenation.
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Affiliation(s)
- Huagang HOU
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover,
NH, 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center,
Lebanon, NH 03756, USA
| | - Ruhong DONG
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover,
NH, 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center,
Lebanon, NH 03756, USA
| | - Jean P. LARIVIERE
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover,
NH, 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center,
Lebanon, NH 03756, USA
| | - Sriram P. MUPPARAJU
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover,
NH, 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center,
Lebanon, NH 03756, USA
| | - Harold M. SWARTZ
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover,
NH, 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center,
Lebanon, NH 03756, USA
| | - Nadeem KHAN
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover,
NH, 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center,
Lebanon, NH 03756, USA
- Contact information, Phone: 1-603-6533591, Fax: 1-603-6501717,
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15
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Abstract
Reactive oxygen/nitrogen species (ROS/RNS) have been increasingly recognized as important mediators and play a number of critical roles in cell injury, metabolism, disease pathology, diagnosis, and clinical treatment. Electron paramagnetic resonance (EPR) spectroscopy enables the spectral information at certain spatial position, and, from the observed line-width and signal intensity, the localized tissue oxygenation, and tissue redox status can be determined. We applied in vivo EPR oximetry and redoximetry technique and implemented its physiological/pathophysiological applications, along with the use of biocompatible lithium pthalocyanine (liPc) and nitroxide redox sensitive probes, on in vivo tissue oxygenation and redox profile of the ischemic and reperfused heart in living animals. We have observed that the hypoxia during myocardial ischemia limited mitochondrial respiration and caused a shift of tissue redox status to a more reduced state. ROS/RNS generated at the beginning of reperfusion not only caused a shift of redox status to a more oxidized state which may contribute to the postischemic myocardial injury, but also a marked suppression of in vivo tissue O(2) consumption in the postischemic heart through modulation of mitochondrial respiration based on alterations in enzyme activity and mRNA expression of NADH dehydrogenase (NADH-DH) and cytochrome c oxidase (CcO). In addition, ischemic preconditioning was found to be able to markedly attenuate postischemic myocardial hyperoxygenation with less ROS/RNS generation and preservation of mitochondrial O(2) metabolism, due to conserved NADH-DH and CcO activities. These studies have demonstrated that EPR oximetry and redoximetry techniques have advanced to a stage that enables in-depth insight in the process of ischemia reperfusion injury.
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Affiliation(s)
- Guanglong He
- The Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA.
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16
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Abstract
Free radicals are highly reactive compounds that play an essential role in many biological processes, both beneficial and deleterious. Detection and quantification of these species is critical to develop a better understanding of normal and pathophysiological functions at the cellular and tissue levels. Electron paramagnetic resonance (EPR) spectroscopy is the technique most commonly used for this purpose through the detection of exogenous probes or spin traps that interact with the free radical species of interest. Over the past several years, the spatial and temporal distribution of free radicals within cells and tissues has been of particular interest. This chapter briefly explains the principles and challenges in the use of EPR for biological samples and introduces the concept of EPR for free radical imaging purposes. In addition, specific examples are given for the use of EPR imaging in four principal areas: free radical probes, nitric oxide (NO), redox state, and oxygen (O(2)) concentration.
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Affiliation(s)
- Deepti S Vikram
- Department of Internal Medicine, Center for Biomedical EPR Spectroscopy and Imaging, Comprehensive Cancer Center, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
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17
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In vivo measurement of tissue oxygen using electron paramagnetic resonance spectroscopy with oxygen-sensitive paramagnetic particle, lithium phthalocyanine. Methods Mol Biol 2010; 610:29-39. [PMID: 20013170 DOI: 10.1007/978-1-60327-029-8_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The partial pressure of oxygen (pO(2)) plays a determining role in the energy metabolism of aerobic cells. However, low pO(2) level induces pathophysiological conditions such as tumor hypoxia, ischemia or reperfusion injury, and delayed/altered wound healing. Especially, pO(2) level in the tumor is known to be related to tumor progression and effectiveness of radiotherapy. To monitor the pO(2) levels in vivo, continuous wave (CW) and time-domain (TD) electron paramagnetic resonance (EPR) spectroscopy method was used, in which surface coil resonator and Lithium phthalocyanine (LiPc) as oxygen sensor were crucial. Once LiPc particles are embedded in a desired location of organ/tissue, the pO(2) level can be monitored repeatedly and non-invasively. This method is based on the effect of oxygen concentration on the EPR spectra of LiPc which offers several advantages as follows: (1) high sensitivity, (2) minimum invasiveness, (3) repeated measurements, (4) absence of toxicity (non-toxic), and (5) measurement in a local region of the tissue with embedded LiPc. Therefore, in this chapter, we describe the method using CW and TD EPR spectroscopy with oxygen-sensitive particle, LiPc, for in vivo monitoring of oxygen.
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18
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Meenakshisundaram G, Eteshola E, Pandian RP, Bratasz A, Selvendiran K, Lee SC, Krishna MC, Swartz HM, Kuppusamy P. Oxygen sensitivity and biocompatibility of an implantable paramagnetic probe for repeated measurements of tissue oxygenation. Biomed Microdevices 2009; 11:817-26. [PMID: 19319683 PMCID: PMC2756533 DOI: 10.1007/s10544-009-9298-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The use of oxygen-sensing water-insoluble paramagnetic probes, such as lithium octa-n-butoxynaphthalocyanine (LiNc-BuO), enables repeated measurements of pO(2) from the same location in tissue by electron paramagnetic resonance (EPR) spectroscopy. In order to facilitate direct in vivo application, and hence eventual clinical applicability, of LiNc-BuO, we encapsulated LiNc-BuO microcrystals in polydimethylsiloxane (PDMS), an oxygen-permeable and bioinert polymer, and developed an implantable chip. In vitro evaluation of the chip, performed under conditions of sterilization, high-energy irradiation, and exposure to cultured cells, revealed that it is biostable and biocompatible. Implantation of the chip in the gastrocnemius muscle tissue of mice showed that it is capable of repeated and real-time measurements of tissue oxygenation for an extended period. Functional evaluation using a murine tumor model established the suitability and applicability of the chip for monitoring tumor oxygenation. This study establishes PDMS-encapsulated LiNc-BuO as a promising choice of probe for clinical EPR oximetry.
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Affiliation(s)
- Guruguhan Meenakshisundaram
- Department of Internal Medicine, Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA
| | - Edward Eteshola
- Department of Biomedical Engineering, Ohio State University, Columbus, OH 43210, USA
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA
| | - Ramasamy P. Pandian
- Department of Internal Medicine, Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA
| | - Anna Bratasz
- Department of Internal Medicine, Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA
| | - Karuppaiyah Selvendiran
- Department of Internal Medicine, Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA
| | - Stephen C. Lee
- Department of Biomedical Engineering, Ohio State University, Columbus, OH 43210, USA
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA
| | - Murali C. Krishna
- Biophysics Spectroscopy Section, Radiation Biology Branch, National Cancer Institute, Bethesda, MD 20892, USA
| | - Harold M. Swartz
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover, NH 03755, USA
| | - Periannan Kuppusamy
- Department of Internal Medicine, Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH 43210, USA
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19
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Eteshola E, Pandian RP, Lee SC, Kuppusamy P. Polymer coating of paramagnetic particulates for in vivo oxygen-sensing applications. Biomed Microdevices 2009; 11:379-87. [PMID: 19083100 DOI: 10.1007/s10544-008-9244-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Crystalline lithium phthalocyanine (LiPc) can be used to sense oxygen. To enhance biocompatibility/stability of LiPc, we encapsulated LiPc in Teflon AF (TAF), cellulose acetate (CA), and polyvinyl acetate (PVAc) (TAF, previously used to encapsulate LiPc, was a comparator). We identified water-miscible solvents that don't dissolve LiPc crystals, but are solvents for the polymers, and encapsulated crystals by solvent evaporation. Oxygen sensitivity of films was characterized in vitro and in vivo. Encapsulation did not change LiPc oximetry properties in vitro at anoxic conditions or varying partial pressures of oxygen (pO2). EPR linewidth of encapsulated particles was linear with pO2, responding to pO2 changes quickly and reproducibly for dynamic measurements. Encapsulated LiPc was unaffected by biological oxidoreductants, stable in vivo for four weeks. Oximetry, stability and biocompatibility properties of LiPc films were comparable, but both CA and PVAc films are cheaper, and easier to fabricate and handle than TAF films, making them superior.
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Affiliation(s)
- Edward Eteshola
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA
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20
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Inagawa M, Yoshikawa H, Yokoyama T, Awaga K. Electrochemical structural transformation and reversible doping/dedoping of lithium phthalocyanine thin films. Chem Commun (Camb) 2009:3389-91. [DOI: 10.1039/b902903f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Vikram DS, Ahmad R, Pandian RP, Petryakov S, Kuppusamy P. Evaluation of oxygen-response times of phthalocyanine-based crystalline paramagnetic spin probes for EPR oximetry. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2008; 193:127-132. [PMID: 18479953 PMCID: PMC2722937 DOI: 10.1016/j.jmr.2008.04.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Revised: 04/09/2008] [Accepted: 04/24/2008] [Indexed: 05/26/2023]
Abstract
The goal of the present study was to evaluate the temporal response of particulate-based EPR oximetry probes to changes in partial pressure of oxygen (pO(2)). In order to accurately evaluate the oxygen-response time, we developed a method for rapid modulation of pO(2) in a chamber containing the probe using an oscillator-driven speaker-diaphragm setup. The apparatus was capable of producing sinusoidal changes in pO(2) at frequencies up to 300 Hz or more. The pressure-modulation setup was used to evaluate the temporal response of some of the most commonly used phthalocyanine-based particulate probes. For validation, the time-response of the probes was compared to that of a high sensitivity pressure sensor. The results revealed that some particulate probes could respond to changes in pO(2) with a temporal response of 3.3 ms (300 Hz). The observations were interpreted in the light of their crystalline packing in favor of oxygen diffusion. The results of the present study should enable the selection of probes for oximetry applications requiring high temporal resolution.
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22
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Vikram DS, Bratasz A, Ahmad R, Kuppusamy P. A comparative evaluation of EPR and OxyLite oximetry using a random sampling of pO(2) in a murine tumor. Radiat Res 2007; 168:308-15. [PMID: 17705635 PMCID: PMC4608498 DOI: 10.1667/rr0854.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Accepted: 04/17/2007] [Indexed: 11/03/2022]
Abstract
Methods currently available for the measurement of oxygen concentrations (oximetry) in viable tissues differ widely from each other in their methodological basis and applicability. The goal of this study was to compare two novel methods, particulate-based electron paramagnetic resonance (EPR) and OxyLite oximetry, in an experimental tumor model. EPR oximetry uses implantable paramagnetic particulates, whereas OxyLite uses fluorescent probes affixed on a fiber-optic cable. C3H mice were transplanted with radiation-induced fibrosarcoma (RIF-1) tumors in their hind limbs. Lithium phthalocyanine (LiPc) microcrystals were used as EPR probes. The pO(2) measurements were taken from random locations at a depth of approximately 3 mm within the tumor either immediately or 48 h after implantation of LiPc. Both methods revealed significant hypoxia in the tumor. However, there were striking differences between the EPR and OxyLite readings. The differences were attributed to the volume of tissue under examination and the effect of needle invasion at the site of measurement. This study recognizes the unique benefits of EPR oximetry in terms of robustness, repeatability and minimal invasiveness.
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Affiliation(s)
| | | | | | - Periannan Kuppusamy
- Address for correspondence: Ohio State University, 420 West 12th Ave., Room 114, Columbus, OH 43210;
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23
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Abstract
The purpose of this review is to provide an overview of the methods available for imaging tissue oxygenation. The following imaging methods are reviewed: phosphorescence, near-infrared (NIR), positron emission tomography (PET), magnetic resonance imaging ((19)F MRI and BOLD MRI), and electron paramagnetic resonance (EPR). The methods are based on different principles and differ in their ability to accurately quantify tissue oxygenation, either the absolute value of a particular measure of oxygenation (partial pressure of oxygen, concentration), or a parameter related to it (oxygen saturation). Methods that can provide images of relative changes in oxygenation or visualization of hypoxia in a specific tissue of interest are also considered valuable tools for biomedical research and clinical applications.
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Affiliation(s)
- Deepti S Vikram
- Center for Biomedical EPR Spectroscopy and Imaging, Comprehensive Cancer Center, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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24
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Zhu X, Liu B, Zhou S, Chen YR, Deng Y, Zweier JL, He G. Ischemic preconditioning prevents in vivo hyperoxygenation in postischemic myocardium with preservation of mitochondrial oxygen consumption. Am J Physiol Heart Circ Physiol 2007; 293:H1442-50. [PMID: 17513495 DOI: 10.1152/ajpheart.00256.2007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ischemic preconditioning (IPC) strongly protects against ischemia-reperfusion injury; however, its effect on subsequent myocardial oxygenation is unknown. Therefore, we determine in an in vivo mouse model of regional ischemia and reperfusion (I/R) if IPC attenuates postischemic myocardial hyperoxygenation and decreases formation of reactive oxygen/nitrogen species (ROS/RNS), with preservation of mitochondrial function. The following five groups of mice were studied: sham, control (I/R), ischemic preconditioning (IPC + I/R, 3 cycles of 5 min coronary occlusion/5 min reperfusion) and IPC + I/R N(G)-nitro-L-arginine methyl ester treated, and IPC + I/R eNOS knockout mice. I/R and IPC + I/R mice were subjected to 30 min regional ischemia followed by 60 min reperfusion. Myocardial Po(2) and redox state were monitored by electron paramagnetic resonance spectroscopy. In the IPC + I/R, but not the I/R group, regional blood flow was increased after reperfusion. Po(2) upon reperfusion increased significantly above preischemic values in I/R but not in IPC + I/R mice. Tissue redox state was measured from the reduction rate of a spin probe, and this rate was 60% higher in IPC than in non-IPC hearts. Activities of NADH dehydrogenase (NADH-DH) and cytochrome c oxidase (CcO) were reduced in I/R mice after 60 min reperfusion but conserved in IPC + I/R mice compared with sham. There were no differences in NADH-DH and CcO expression in I/R and IPC + I/R groups compared with sham. After 60 min reperfusion, strong nitrotyrosine formation was observed in I/R mice, but only weak staining was observed in IPC + I/R mice. Thus IPC markedly attenuates postischemic myocardial hyperoxygenation with less ROS/RNS generation and preservation of mitochondrial O(2) metabolism because of conserved NADH-DH and CcO activities.
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Affiliation(s)
- Xuehai Zhu
- Center for Biomedical Electron Paramagnetic Resonance Spectroscopy and Imaging, Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, Ohio, USA
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25
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Ahmad R, Vikram DS, Petryakov S, Deng Y, Zweier JL, Kuppusamy P, Clymer B. Automated on-the-fly detection and correction procedure for EPR imaging data acquisition. Magn Reson Med 2006; 56:644-53. [PMID: 16878301 PMCID: PMC1839058 DOI: 10.1002/mrm.20967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fast and reliable data acquisition is a major requirement for successful and useful biological electron paramagnetic resonance imaging (EPRI) experiments. Even a technologically advanced and professionally supervised EPRI system can exhibit instabilities initiated by perturbations such as animal motion, microphonics, and temperature changes. As a result, part of an acquired data set may become corrupted with excessive noise and distortions, which in turn may degrade the quality of the reconstructed image. In this work an automated scheme to monitor the system performance and stability over the course of an experiment is demonstrated. This method ensures that the quality of the acquired data is maintained during the experiment. For this purpose, four parameters including noise content and integration of each acquired projection are quantified and measured against those of the zero-gradient (ZG) projection, which is set as a quality benchmark. Projections with parameter values that differ substantially from the expected values are identified as damaged and consequently are reacquired. Therefore, the proposed technique not only effectively monitors the quality of acquisition, it also saves a substantial amount of acquisition time because it eliminates the necessity of repeating the entire experiment in cases in which only a small fraction of the data are corrupted.
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Affiliation(s)
- Rizwan Ahmad
- Department of Electrical and Computer Engineering, Ohio State University, College of Engineering, Columbus, Ohio 43210, USA
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26
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Pandian RP, Dang V, Manoharan PT, Zweier JL, Kuppusamy P. Effect of nitrogen dioxide on the EPR property of lithium octa-n-butoxy 2,3-naphthalocyanine (LiNc-BuO) microcrystals. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2006; 181:154-61. [PMID: 16690337 DOI: 10.1016/j.jmr.2006.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Revised: 04/05/2006] [Accepted: 04/05/2006] [Indexed: 05/09/2023]
Abstract
Lithium octa-n-butoxy-naphthalocyanine (LiNc-BuO) is a stable free radical that can be detected by electron paramagnetic resonance (EPR) spectroscopy. Previously we have reported that microcrystals of LiNc-BuO exhibit a single sharp EPR peak, whose width varies linearly with the partial pressure of paramagnetic molecules such as oxygen and nitric oxide. In this report, we present the effect of nitrogen dioxide (NO2), which is also a paramagnetic molecule, on the EPR properties of LiNc-BuO. The gas-sensing property of LiNc-BuO is attributed to the open molecular framework of the crystal structure which is arranged with wide channels capable of accommodating large molecules such as NO2. The EPR linewidth of LiNc-BuO was highly sensitive to the partial pressure of NO2 in the gas mixture. The line-broadening was quick and reversible in the short-term for low concentration of NO2. However, the EPR signal intensity decreased with time of exposure, apparently due to a reaction of NO2 with LiNc-BuO crystals to give diamagnetic products. The results suggested that LiNc-BuO may be a useful probe for the determination of trace amounts of NO2 using EPR spectroscopy.
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Affiliation(s)
- Ramasamy P Pandian
- Center for Biomedical EPR Spectroscopy and Imaging, Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA
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27
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Ahmad R, Clymer B, Deng Y, He G, Vikram D, Kuppusamy P, Zweier JL. Optimization of data acquisition for EPR imaging. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2006; 179:263-72. [PMID: 16458030 DOI: 10.1016/j.jmr.2005.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Revised: 12/24/2005] [Accepted: 12/27/2005] [Indexed: 05/06/2023]
Abstract
In electron paramagnetic resonance imaging (EPRI), long data acquisition time is one of the major problems limiting successful and useful biological EPRI experiments. Depending on the configuration (spatial distribution of paramagnetic species), information embedded in some objects can be characterized using a smaller number of projections, while others may require significantly larger number of projections to generate similar results. In order to optimize the acquisition process, it is therefore important to acquire a different number of projections for different objects. In this paper, a prediction scheme is demonstrated that can determine the number of projections required to achieve a preset reconstruction quality for a given object. After acquiring first few projections, corresponding partially filled k-space is analyzed. The complexity of data (to interpolate) in k-space is quantified and used to predict the number of required projections. All the projections are acquired using a mean-square difference-based adaptive acquisition technique that is also demonstrated in this work. The purpose of this non-uniform acquisition is to reduce redundancy in the acquired data which in turn decreases the number of projections required for the given object. It is also demonstrated that the performance of non-uniform acquisition is content dependant, and for certain configurations it may not be as effective as uniform acquisition in preserving signal from low intensity regions. The prediction scheme along with the non-uniform acquisition is tested using computer simulations, imaging of experimental phantoms, and in vivo imaging. Results indicate that the proposed method may save up to 50% of acquisition time. The techniques in this manuscript are described for 2D spatial imaging but can be extended to 3D imaging.
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Affiliation(s)
- Rizwan Ahmad
- Department of Electrical and Computer Engineering, The Ohio State University, College of Engineering, Columbus, Ohio 43210, USA
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28
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Pandian RP, Kim YI, Woodward PM, Zweier JL, Manoharan PT, Kuppusamy P. The open molecular framework of paramagnetic lithium octabutoxy-naphthalocyanine: implications for the detection of oxygen and nitric oxide using EPR spectroscopy. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b517976a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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