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Petryakov SV, Kmiec MM, Ubert CS, Kassey VB, Schaner PE, Kuppusamy P. Surface dielectric resonator for in vivo EPR measurements. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 362:107690. [PMID: 38692250 PMCID: PMC11102834 DOI: 10.1016/j.jmr.2024.107690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/16/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024]
Abstract
This research report describes a novel surface dielectric resonator (SDR) with a flexible connector for in vivo electron paramagnetic resonance (EPR) spectroscopy. Contrary to the conventional cavity or surface loop-gap resonators, the newly developed SDR is constructed from a ceramic dielectric material, and it is tuned to operate at the L-band frequency band (1.15 GHz) in continuous-wave mode. The SDR is designed to be critically coupled and capable of working with both very lossy samples, such as biological tissues, and non-lossy materials. The SDR was characterized using electromagnetic field simulations, assessed for sensitivity with a B1 field-perturbation method, and validated with tissue phantoms using EPR measurements. The results showed remarkably higher sensitivity in lossy tissue phantoms than the previously reported multisegment surface-loop resonators. The new SDR can provide potential new insights for advancements in the application of in vivo EPR spectroscopy for biological measurements, including clinical oximetry.
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Affiliation(s)
- Sergey V Petryakov
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Maciej M Kmiec
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Conner S Ubert
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA; Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Victor B Kassey
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Philip E Schaner
- Department of Radiation Oncology and Applied Sciences, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Periannan Kuppusamy
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA; Thayer School of Engineering, Dartmouth College, Hanover, NH, USA; Department of Radiation Oncology and Applied Sciences, Geisel School of Medicine at Dartmouth, Hanover, NH, USA.
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Schaner PE, Williams BB, Chen EY, Pettus JR, Schreiber WA, Kmiec MM, Jarvis LA, Pastel DA, Zuurbier RA, DiFlorio-Alexander RM, Paydarfar JA, Gosselin BJ, Barth RJ, Rosenkranz KM, Petryakov SV, Hou H, Tse D, Pletnev A, Flood AB, Wood VA, Hebert KA, Mosher RE, Demidenko E, Swartz HM, Kuppusamy P. First-In-Human Study in Cancer Patients Establishing the Feasibility of Oxygen Measurements in Tumors Using Electron Paramagnetic Resonance With the OxyChip. Front Oncol 2021; 11:743256. [PMID: 34660306 PMCID: PMC8517507 DOI: 10.3389/fonc.2021.743256] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 09/07/2021] [Indexed: 01/23/2023] Open
Abstract
OBJECTIVE The overall objective of this clinical study was to validate an implantable oxygen sensor, called the 'OxyChip', as a clinically feasible technology that would allow individualized tumor-oxygen assessments in cancer patients prior to and during hypoxia-modification interventions such as hyperoxygen breathing. METHODS Patients with any solid tumor at ≤3-cm depth from the skin-surface scheduled to undergo surgical resection (with or without neoadjuvant therapy) were considered eligible for the study. The OxyChip was implanted in the tumor and subsequently removed during standard-of-care surgery. Partial pressure of oxygen (pO2) at the implant location was assessed using electron paramagnetic resonance (EPR) oximetry. RESULTS Twenty-three cancer patients underwent OxyChip implantation in their tumors. Six patients received neoadjuvant therapy while the OxyChip was implanted. Median implant duration was 30 days (range 4-128 days). Forty-five successful oxygen measurements were made in 15 patients. Baseline pO2 values were variable with overall median 15.7 mmHg (range 0.6-73.1 mmHg); 33% of the values were below 10 mmHg. After hyperoxygenation, the overall median pO2 was 31.8 mmHg (range 1.5-144.6 mmHg). In 83% of the measurements, there was a statistically significant (p ≤ 0.05) response to hyperoxygenation. CONCLUSIONS Measurement of baseline pO2 and response to hyperoxygenation using EPR oximetry with the OxyChip is clinically feasible in a variety of tumor types. Tumor oxygen at baseline differed significantly among patients. Although most tumors responded to a hyperoxygenation intervention, some were non-responders. These data demonstrated the need for individualized assessment of tumor oxygenation in the context of planned hyperoxygenation interventions to optimize clinical outcomes.
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Affiliation(s)
- Philip E. Schaner
- Department of Medicine, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Benjamin B. Williams
- Department of Medicine, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Eunice Y. Chen
- Department of Surgery, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Jason R. Pettus
- Department of Pathology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Wilson A. Schreiber
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Maciej M. Kmiec
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Lesley A. Jarvis
- Department of Medicine, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - David A. Pastel
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Rebecca A. Zuurbier
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Roberta M. DiFlorio-Alexander
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Joseph A. Paydarfar
- Department of Surgery, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Benoit J. Gosselin
- Department of Surgery, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Richard J. Barth
- Department of Surgery, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Kari M. Rosenkranz
- Department of Surgery, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Sergey V. Petryakov
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Huagang Hou
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Dan Tse
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Alexandre Pletnev
- Department of Chemistry, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Ann Barry Flood
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Victoria A. Wood
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Kendra A. Hebert
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Robyn E. Mosher
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Eugene Demidenko
- Department of Biomedical Data Science, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Harold M. Swartz
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Periannan Kuppusamy
- Department of Medicine, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
- Department of Radiology, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
- Department of Chemistry, Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, and Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
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Electrospun nanofiber-based cancer sensors: A review. Int J Pharm 2020; 583:119364. [DOI: 10.1016/j.ijpharm.2020.119364] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/27/2022]
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Li C, Huang Z, Gao N, Zheng J, Guan J. Injectable, thermosensitive, fast gelation, bioeliminable, and oxygen sensitive hydrogels. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 99:1191-1198. [PMID: 30889653 PMCID: PMC7368179 DOI: 10.1016/j.msec.2019.02.075] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/06/2019] [Accepted: 02/20/2019] [Indexed: 01/09/2023]
Abstract
The decrease of tissue oxygen content due to pathological conditions leads to severe cell death and tissue damage. Restoration of tissue oxygen content is the primary treatment goal. To accurately and efficiently assess efficacy of a treatment, minimally invasive, and long-term detection of oxygen concentration in the same tissue location represents a clinically attractive strategy. Among the different oxygen concentration measurement approaches, electron paramagnetic resonance (EPR) has the potential to accomplish this. Yet there lacks injectable EPR probes that can maintain a consistent concentration at the same tissue location during treatment period to acquire a stable EPR signal, and can finally be eliminated from body without retrieval. Herein, we developed injectable and bioeliminable hydrogel-based polymeric EPR probes that exhibited fast gelation rate, slow weight loss rate, and high oxygen sensitivity. The probe was based on N-Isopropylacrylamide (NIPAAm), 2-hydroxyethyl methacrylate (HEMA), dimethyl-γ-butyrolactone acrylate (DBA), and tetrathiatriarylmethyl (TAM) radical. The injectable probes can be implanted into tissues using a minimally invasive injection approach. The high gelation rate (~10 s) allowed the probes to quickly solidify upon injection to have a high retention in tissues. The polymeric probes overcame the toxicity issue of current small molecule EPR probes. The probes can be gradually hydrolyzed. Upon complete hydrolysis, the probes became water soluble at 37 °C, thus having the potential to be removed from the body by urinary system. The probes showed slow weight loss rate so as to maintain EPR signal intensity for extended periods while retaining in a certain tissue location. The probes remained their high oxygen sensitivity after in vitro hydrolysis and in vivo implantation for 4 weeks. These hydrogel-based EPR probes have attractive properties for in vivo oxygen detection.
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Affiliation(s)
- Chao Li
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Zheng Huang
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Ning Gao
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Jie Zheng
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jianjun Guan
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA; Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO 63130, USA.
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Kmiec MM, Hou H, Lakshmi Kuppusamy M, Drews TM, Prabhat AM, Petryakov SV, Demidenko E, Schaner PE, Buckey JC, Blank A, Kuppusamy P. Transcutaneous oxygen measurement in humans using a paramagnetic skin adhesive film. Magn Reson Med 2018; 81:781-794. [PMID: 30277275 DOI: 10.1002/mrm.27445] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/11/2018] [Accepted: 06/11/2018] [Indexed: 01/20/2023]
Abstract
PURPOSE Transcutaneous oxygen tension (TcpO2 ) provides information about blood perfusion in the tissue immediately below the skin. These data are valuable in assessing wound healing problems, diagnosing peripheral vascular/arterial insufficiency, and predicting disease progression or the response to therapy. Currently, TcpO2 is primarily measured using electrochemical skin sensors, which consume oxygen and are prone to calibration errors. The goal of the present study was to develop a reliable method for TcpO2 measurement in human subjects. METHODS We have developed a novel TcpO2 oximetry method based on electron paramagnetic resonance (EPR) principles with an oxygen-sensing skin adhesive film, named the superficial perfusion oxygen tension (SPOT) chip. The SPOT chip is a 3-mm diameter, 60-μm thick circular film composed of a stable paramagnetic oxygen sensor. The chip is covered with an oxygen-barrier material on one side and secured on the skin by a medical adhesive transfer tape to ensure that only the oxygen that diffuses through the skin surface is measured. The method quantifies TcpO2 through the linewidth of the EPR spectrum. RESULTS Repeated measurements using a cohort of 10 healthy human subjects showed that the TcpO2 measurements were robust, reliable, and reproducible. The TcpO2 values ranged from 7.8 ± 0.8 to 22.0 ± 1.0 mmHg in the volar forearm skin (N = 29) and 8.1 ± 0.3 to 23.4 ± 1.3 mmHg in the foot (N = 86). CONCLUSIONS The results demonstrated that the SPOT chip can measure TcpO2 reliably and repeatedly under ambient conditions. The SPOT chip method could potentially be used to monitor TcpO2 in the clinic.
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Affiliation(s)
- Maciej M Kmiec
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - Huagang Hou
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - M Lakshmi Kuppusamy
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - Thomas M Drews
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts
| | - Anjali M Prabhat
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - Sergey V Petryakov
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - Eugene Demidenko
- Department of Biomedical Data Sciences, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - Philip E Schaner
- Department of Medicine, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - Jay C Buckey
- Department of Medicine, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire
| | - Aharon Blank
- Schulich Faculty of Chemistry Technion, Israel Institute of Technology, Haifa, Israel
| | - Periannan Kuppusamy
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Lebanon, New Hampshire.,Department of Chemistry, University of Massachusetts, Amherst, Massachusetts
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Abstract
EPR (electron paramagnetic resonance) based biological oximetry is a powerful tool that accurately and repeatedly measures tissue oxygen levels. In vivo determination of oxygen in tissues is crucial for the diagnosis and treatment of a number of diseases. Here, we report the first successful fabrication and remarkable properties of nanofiber sensors for EPR-oximetry applications. Lithium octa-n-butoxynaphthalocyanine (LiNc- BuO), an excellent paramagnetic oxygen sensor, was successfully encapsulated in 300-500 nm diameter fibers consisting of a core of polydimethylsiloxane (PDMS) and a shell of polycaprolactone (PCL) by electrospinning. This core-shell nanosensor (LiNc-BuO-PDMS-PCL) shows a linear dependence of linewidth versus oxygen partial pressure (pO2). The nanofiber sensors have response and recovery times of 0.35 s and 0.55 s, respectively, these response and recovery times are ~12 times and ~218 times faster than those previously reported for PDMS-LiNc-BuO chip sensors. This greater responsiveness is likely due to the high porosity and excellent oxygen permeability of the nanofibers. Electrospinning of the structurally flexible PDMS enabled the fabrication of fibers having tailored spin densities. Core-shell encapsulation ensures the non-exposure of embedded LiNc-BuO and mitigates potential biocompatibility concerns. In vitro evaluation of the fiber performed under exposure to cultured cells showed that it is both stable and biocompatible. The unique combination of biocompatibility due to the PCL 'shell,' the excellent oxygen transparency of the PDMS core, and the excellent oxygen-sensing properties of LiNc-BuO makes LiNc-BuO-PDMS-PCL platform promising for long-term oximetry and repetitive oxygen measurements in both biological systems and clinical applications.
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Frank J, Gündel D, Drescher S, Thews O, Mäder K. Injectable LiNc-BuO loaded microspheres as in vivo EPR oxygen sensors after co-implantation with tumor cells. Free Radic Biol Med 2015; 89:741-9. [PMID: 26459034 DOI: 10.1016/j.freeradbiomed.2015.10.401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 10/03/2015] [Accepted: 10/08/2015] [Indexed: 10/22/2022]
Abstract
Electron paramagnetic resonance (EPR) oximetry is a technique which allows accurate and repeatable oxygen measurements. We encapsulated a highly oxygen sensitive particulate EPR spin probe into microparticles to improve its dispersibility and, hence, facilitate the administration. These biocompatible, non-toxic microspheres contained 5-10 % (w/w) spin probe and had an oxygen sensitivity of 0.60 ± 0.01 µT/mmHg. To evaluate the performance of the microparticles as oxygen sensors, they were co-implanted with syngeneic tumor cells in 2 different rat strains. Thus, tissue injury was avoided and the microparticles were distributed all over the tumor tissue. Dynamic changes of the intratumoral oxygen partial pressure during inhalation of 8 %, 21 %, or 100 % oxygen were monitored in vivo by EPR spectroscopy and quantified. Values were verified in vivo by invasive fluorometric measurements using Oxylite probes and ex vivo by pimonidazole adduct accumulation. There were no hints that the tumor physiology or tissue oxygenation had been altered by the microparticles. Hence, these microprobes offer great potential as oxygen sensors in preclinical research, not only for EPR spectroscopy but also for EPR imaging. For instance, the assessment of tissue oxygenation during therapeutic interventions might help understanding pathophysiological processes and lead to an individualized treatment planning or the use of formulations with hypoxia triggered release of active agents.
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Affiliation(s)
- Juliane Frank
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany
| | - Daniel Gündel
- Julius-Bernstein-Institute of Physiology, Martin Luther University Halle-Wittenberg, Magdeburger Str. 6, 06112 Halle (Saale), Germany
| | - Simon Drescher
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany
| | - Oliver Thews
- Julius-Bernstein-Institute of Physiology, Martin Luther University Halle-Wittenberg, Magdeburger Str. 6, 06112 Halle (Saale), Germany.
| | - Karsten Mäder
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany.
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Swartz HM, Williams BB, Zaki BI, Hartford AC, Jarvis LA, Chen EY, Comi RJ, Ernstoff MS, Hou H, Khan N, Swarts SG, Flood AB, Kuppusamy P. Clinical EPR: unique opportunities and some challenges. Acad Radiol 2014; 21:197-206. [PMID: 24439333 DOI: 10.1016/j.acra.2013.10.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 10/03/2013] [Accepted: 10/14/2013] [Indexed: 11/29/2022]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy has been well established as a viable technique for measurement of free radicals and oxygen in biological systems, from in vitro cellular systems to in vivo small animal models of disease. However, the use of EPR in human subjects in the clinical setting, although attractive for a variety of important applications such as oxygen measurement, is challenged with several factors including the need for instrumentation customized for human subjects, probe, and regulatory constraints. This article describes the rationale and development of the first clinical EPR systems for two important clinical applications, namely, measurement of tissue oxygen (oximetry) and radiation dose (dosimetry) in humans. The clinical spectrometers operate at 1.2 GHz frequency and use surface-loop resonators capable of providing topical measurements up to 1 cm depth in tissues. Tissue pO2 measurements can be carried out noninvasively and repeatedly after placement of an oxygen-sensitive paramagnetic material (currently India ink) at the site of interest. Our EPR dosimetry system is capable of measuring radiation-induced free radicals in the tooth of irradiated human subjects to determine the exposure dose. These developments offer potential opportunities for clinical dosimetry and oximetry, which include guiding therapy for individual patients with tumors or vascular disease by monitoring of tissue oxygenation. Further work is in progress to translate this unique technology to routine clinical practice.
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Affiliation(s)
- Harold M Swartz
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766.
| | - Benjamin B Williams
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Bassem I Zaki
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Alan C Hartford
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Lesley A Jarvis
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Eunice Y Chen
- Department of Surgery, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Richard J Comi
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Marc S Ernstoff
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Huagang Hou
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Nadeem Khan
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Steven G Swarts
- Dept. of Radiation Oncology, University of Florida, Gainesville, FL
| | - Ann B Flood
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Periannan Kuppusamy
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
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Qi D, Zhang L, Jiang J. Toward panchromatic organic functional molecules: Density functional theory study on the nature of the broad UV–Vis–NIR spectra of substituted tetra(azulene)porphyrins. J Mol Graph Model 2012; 38:304-13. [DOI: 10.1016/j.jmgm.2012.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/04/2012] [Accepted: 06/04/2012] [Indexed: 12/19/2022]
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Evaluation of Lithium Naphthalocyanine (LiNc) Microcrystals for Biological EPR Oximetry. OXYGEN TRANSPORT TO TISSUE XXXII 2011; 701:29-36. [DOI: 10.1007/978-1-4419-7756-4_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Pandian RP, Meenakshisundaram G, Bratasz A, Eteshola E, Lee SC, Kuppusamy P. An implantable Teflon chip holding lithium naphthalocyanine microcrystals for secure, safe, and repeated measurements of pO2 in tissues. Biomed Microdevices 2010; 12:381-7. [PMID: 20058084 PMCID: PMC2860037 DOI: 10.1007/s10544-009-9394-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Lithium naphthalocyanine (LiNc) is a crystalline material that has significant potential as a probe for EPR (electron paramagnetic resonance)-based biological oximetry (Pandian et al. J. Mater. Chem. 19:4138-4147, 2009a). However, implantation of LiNc crystals in tissues in raw or neat form is undesirable since dispersion of crystals in tissue may lead to loss of EPR signal, while also exacerbating biocompatibility concerns due to tissue exposure. To overcome these concerns, we have encapsulated LiNc crystals in an oxygen-permeable polymer, Teflon AF 2400 (TAF). Fabrication of TAF films incorporating LiNc particles (denoted as LiNc:TAF chip) was carried out using solvent-evaporation techniques. The EPR linewidth of LiNc:TAF chip was linearly dependent on oxygen-partial pressure (pO(2)) and did not change significantly relative to neat LiNc crystals. LiNc:TAF chip responded to changes in pO(2) reproducibly, enabling dynamic measurements of oxygenation in real time. The LiNc:TAF chips were stable in tissues for more than 2 months and were capable of providing repeated measurements of tissue oxygenation for extended periods of time. The results demonstrated that the newly fabricated, highly oxygen-sensitive LiNc:TAF chip will enhance the applicability of EPR oximetry for long-term and clinical applications.
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Affiliation(s)
- Ramasamy P. Pandian
- Center for Biomedical and EPR Spectroscopy Imaging, Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
| | - Guruguhan Meenakshisundaram
- Center for Biomedical and EPR Spectroscopy Imaging, Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
| | - Anna Bratasz
- Center for Biomedical and EPR Spectroscopy Imaging, Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
| | - Edward Eteshola
- Department of Biomedical Engineering, Davis Heart and Lung Research Institute, The Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
| | - Stephen C. Lee
- Department of Biomedical Engineering, Davis Heart and Lung Research Institute, The Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA
| | - Periannan Kuppusamy
- Center for Biomedical and EPR Spectroscopy Imaging, Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University, 420 West 12th Avenue, Room 114, Columbus, OH 43210, USA,
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Ahmad R, Kuppusamy P. Theory, instrumentation, and applications of electron paramagnetic resonance oximetry. Chem Rev 2010; 110:3212-36. [PMID: 20218670 PMCID: PMC2868962 DOI: 10.1021/cr900396q] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Rizwan Ahmad
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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14
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Blank A, Halevy R, Shklyar M, Shtirberg L, Kuppusamy P. ESR micro-imaging of LiNc-BuO crystals in PDMS: spatial and spectral grain distribution. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 203:150-155. [PMID: 20045659 DOI: 10.1016/j.jmr.2009.12.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 12/13/2009] [Accepted: 12/14/2009] [Indexed: 05/28/2023]
Abstract
Microcrystals of lithium octa-n-butoxynaphthalocyanine (LiNc-BuO) in a bio-compatible and oxygen-permeable polymer matrix of poly-dimethyl-siloxane (PDMS) can be used for repetitive non-invasive imaging of oxygen in live specimens by means of mm-scale electron spin resonance (ESR) imaging. This probe denoted as "oxychip" was characterized by high-resolution mum-scale ESR microcopy to reveal the fine details of its spatial and spectral properties. The ESR micro-images of a typical oxychip device showed that while the spatial distribution of the microcrystals in the polymer is fairly homogenous (as revealed by optical microscopy), the ESR signal originates only from a very few dominant crystals. Furthermore, spectral-spatial analysis in a microcrystal and a sub-microcrystal spatial resolution reveals that each crystal has a slightly different g-factor and also exhibits variations in linewidth, possibly due to the slightly different individual crystallization process.
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Affiliation(s)
- Aharon Blank
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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15
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Fabrication and physical evaluation of a polymer-encapsulated paramagnetic probe for biomedical oximetry. Biomed Microdevices 2009; 11:773-82. [PMID: 19291409 DOI: 10.1007/s10544-009-9292-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Lithium octa-n-butoxynaphthalocyanine (LiNc-BuO) is a promising probe for biological electron paramagnetic resonance (EPR) oximetry and is being developed for clinical use. However, clinical applicability of LiNc-BuO may be hindered by potential limitations associated with biocompatibility, biodegradation, and migration of individual crystals in tissue. To overcome these limitations, we have encapsulated LiNc-BuO crystals in polydimethyl siloxane (PDMS), an oxygen-permeable and bioinert polymer, to fabricate conveniently implantable and retrievable oxygen-sensing chips. Encapsulation was performed by a simple cast-molding process, giving appreciable control over size, shape, thickness and spin density of chips. The in vitro oxygen response of the chip was linear, reproducible, and not significantly different from that of unencapsulated crystals. Cast-molding of the structurally-flexible PDMS enabled the fabrication of chips with tailored spin densities, and ensured non-exposure of embedded LiNc-BuO, mitigating potential biocompatibility/toxicological concerns. Our results establish PDMS-encapsulated LiNc-BuO as a promising candidate for further biological evaluation and potential clinical application.
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16
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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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17
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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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18
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Liu Y, Villamena FA, Sun J, Wang TY, Zweier JL. Esterified trityl radicals as intracellular oxygen probes. Free Radic Biol Med 2009; 46:876-83. [PMID: 19135524 PMCID: PMC2673998 DOI: 10.1016/j.freeradbiomed.2008.12.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 11/17/2008] [Accepted: 12/11/2008] [Indexed: 10/21/2022]
Abstract
Triarylmethyl (trityl) radicals exhibit high stability and narrow linewidth under physiological conditions which provide high sensitivity and resolution for the measurement of O2 concentrations, making them attractive as EPR oximetry probes. However, the application of previously available compounds has been limited by their poor intracellular permeability. We recently reported the synthesis and characterization of esterified trityl radicals as potential intracellular EPR probes and their oxygen sensitivity, redox properties, and enzyme-mediated hydrolysis were investigated. In this paper, we report the cellular permeability and stability of these trityls in the presence of bovine aortic endothelial cells. Results show that the acetoxymethoxycarbonyl-containing trityl AMT-02 exhibits high stability in the presence of cells and can be effectively internalized. The intracellular hydrolysis of AMT-02 to the carboxylate form of the trityl (CT-03) was also observed. In addition, this internalized trityl probe was applied to measure intracellular O2 concentrations and the effects of menadione and KCN on the rates of O2 consumption in endothelial cells. This study demonstrates that these esterified trityl radicals can function as effective EPR oximetry probes measuring intracellular O2 concentration and consumption.
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Affiliation(s)
- Yangping Liu
- Center for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, Columbus, OH 43210, USA
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19
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Pandian RP, Dolgos M, Marginean C, Woodward PM, Hammel PC, Manoharan PT, Kuppusamy P. Molecular packing and magnetic properties of lithium naphthalocyanine crystals: hollow channels enabling permeability and paramagnetic sensitivity to molecular oxygen. JOURNAL OF MATERIALS CHEMISTRY 2009; 19:4138-4147. [PMID: 19809598 PMCID: PMC2756769 DOI: 10.1039/b901886g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis, structural framework, magnetic and oxygen-sensing properties of a lithium naphthalocyanine (LiNc) radical probe are presented. LiNc was synthesized in the form of a microcrystalline powder using a chemical method and characterized by electron paramagnetic resonance (EPR) spectroscopy, magnetic susceptibility, powder X-ray diffraction analysis, and mass spectrometry. X-Ray powder diffraction studies revealed a structural framework that possesses long, hollow channels running parallel to the packing direction. The channels measured approximately 5.0 × 5.4 Å(2) in the two-dimensional plane perpendicular to the length of the channel, enabling diffusion of oxygen molecules (2.9 × 3.9 Å(2)) through the channel. The powdered LiNc exhibited a single, sharp EPR line under anoxic conditions, with a peak-to-peak linewidth of 630 mG at room temperature. The linewidth was sensitive to surrounding molecular oxygen, showing a linear increase in pO(2) with an oxygen sensitivity of 31.2 mG per mmHg. The LiNc microcrystals can be further prepared as nano-sized crystals without the loss of its high oxygen-sensing properties. The thermal variation of the magnetic properties of LiNc, such as the EPR linewidth, EPR intensity and magnetic susceptibility revealed the existence of two different temperature regimes of magnetic coupling and hence differing columnar packing, both being one-dimensional antiferromagnetic chains but with differing magnitudes of exchange coupling constants. At a temperature of ∼50 K, LiNc crystals undergo a reversible phase transition. The high degree of oxygen-sensitivity of micro- and nano-sized crystals of LiNc, combined with excellent stability, should enable precise and accurate measurements of oxygen concentration in biological systems using EPR spectroscopy.
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Affiliation(s)
- Ramasamy P. Pandian
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Michelle Dolgos
- Department of Chemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - Camelia Marginean
- Department of Physics, The Ohio State University, Columbus, OH 43210, USA
| | - Patrick M. Woodward
- Department of Chemistry, The Ohio State University, Columbus, OH, 43210, USA
| | - P. Chris Hammel
- Department of Physics, The Ohio State University, Columbus, OH 43210, USA
| | | | - Periannan Kuppusamy
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
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20
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Subramanian S, Krishna MC. DANCING WITH THE ELECTRONS: TIME-DOMAIN AND CW IN VIVO EPR IMAGING. MAGNETIC RESONANCE INSIGHTS 2008; 2:43-74. [PMID: 22025900 DOI: 10.4137/mri.s1131] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The progress in the development of imaging the distribution of unpaired electrons in living systems and the functional and the potential diagnostic dimensions of such an imaging process, using Electron Paramagnetic Resonance Imaging (EPRI), is traced from its origins with emphasis on our own work. The importance of EPR imaging stems from the fact that many paramagnetic probes show oxygen dependent spectral broadening. Assessment of in vivo oxygen concentration is an important factor in radiation oncology in treatment-planning and monitoring treatment-outcome. The emergence of narrow-line trairylmethyl based, bio-compatible spin probes has enabled the development of radiofrequency time-domain EPRI. Spectral information in time-domain EPRI can be achieved by generating a time sequence of T(2)* or T(2) weighted images. Progress in CW imaging has led to the use of rotating gradients, more recently rapid scan with direct detection, and a combination of all the three. Very low field MRI employing Dynamic Nuclear polarization (Overhauser effect) is also employed for monitoring tumor hypoxia, and re-oxygenation in vivo. We have also been working on the co-registration of MRI and time domain EPRI on mouse tumor models at 300 MHz using a specially designed resonator assembly. The mapping of the unpaired electron distribution and unraveling the spectral characteristics by using magnetic resonance in presence of stationary and rotating gradients in indeed 'dancing with the (unpaired) electrons', metaphorically speaking.
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Affiliation(s)
- Sankaran Subramanian
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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21
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Som S, Potter LC, Ahmad R, Vikram DS, Kuppusamy P. EPR oximetry in three spatial dimensions using sparse spin distribution. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2008; 193:210-217. [PMID: 18538600 PMCID: PMC2630719 DOI: 10.1016/j.jmr.2008.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 05/01/2008] [Accepted: 05/01/2008] [Indexed: 05/26/2023]
Abstract
A method is presented to use continuous wave electron paramagnetic resonance imaging for rapid measurement of oxygen partial pressure in three spatial dimensions. A particulate paramagnetic probe is employed to create a sparse distribution of spins in a volume of interest. Information encoding location and spectral linewidth is collected by varying the spatial orientation and strength of an applied magnetic gradient field. Data processing exploits the spatial sparseness of spins to detect voxels with nonzero spin and to estimate the spectral linewidth for those voxels. The parsimonious representation of spin locations and linewidths permits an order of magnitude reduction in data acquisition time, compared to four-dimensional tomographic reconstruction using traditional spectral-spatial imaging. The proposed oximetry method is experimentally demonstrated for a lithium octa-n-butoxy naphthalocyanine (LiNc-BuO) probe using an L-band EPR spectrometer.
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Affiliation(s)
- Subhojit Som
- Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Lee C. Potter
- Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Rizwan Ahmad
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Deepti S. Vikram
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Periannan Kuppusamy
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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22
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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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23
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Fujii H, Itoh K, Pandian RP, Sakata M, Kuppusamy P, Hirata H. Measuring brain tissue oxygenation under oxidative stress by ESR/MR dual imaging system. Magn Reson Med Sci 2007; 6:83-9. [PMID: 17690538 DOI: 10.2463/mrms.6.83] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The in vivo measurement of oxygen in tissues is of great interest because of oxygen's fundamental role in life. Many methods have been developed for such measurement, but all have been limited, especially with regard to repeated measurement, degree of invasiveness, and sensitivity. We describe electron spin resonance (ESR) oximetry with paramagnetic oxygen-sensing probe for in vivo measurement of oxygen in brain tissues by home-made ESR/MR dual imaging spectroscopy. Lithium 5, 9, 14, 18, 23, 27, 32, 36-octa-n-butoxy-2,3-naphthlocyanine (LiNc-BuO) radical was employed as the solid oxygen-sensing probe, and we confirmed its ability to report partial pressure of oxygen (pO(2)) in brain tissues of live animals under normal and pathological conditions for more than a month. pO(2) measurements could also be made repeatedly on the same animal and at the same location. The implantation site of LiNc-BuO in examined rats was verified by 0.5 T magnetic resonance (MR) imaging. Septic-shock rats were used to monitor tissue oxygenation during pathological state. A decline in pO(2) levels from severe hypotension during sepsis was detected, and generation of nitric oxide (NO) in brain tissues was confirmed by NO spin trapping. ESR oximetry using oxygen-sensing probe and NO spin-trapping can be used to monitor pO(2) change and NO production simultaneously and repeatedly at the same site in examined animals.
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Affiliation(s)
- Hirotada Fujii
- School of Health Sciences, Sapporo Medical University, Sapporo, Japan.
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24
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Khan M, Kutala VK, Vikram DS, Wisel S, Chacko SM, Kuppusamy ML, Mohan IK, Zweier JL, Kwiatkowski P, Kuppusamy P. Skeletal myoblasts transplanted in the ischemic myocardium enhance in situ oxygenation and recovery of contractile function. Am J Physiol Heart Circ Physiol 2007; 293:H2129-39. [PMID: 17660391 PMCID: PMC7062408 DOI: 10.1152/ajpheart.00677.2007] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is unclear whether oxygen plays a role in stem cell therapy. Hence, the determination of local oxygenation (Po(2)) in the infarct heart and at the site of transplantation may be critical to study the efficacy of cell therapy. To demonstrate this, we have developed an oxygen-sensing paramagnetic spin probes (OxySpin) to monitor oxygenation in the region of cell transplantation using electron paramagnetic resonance (EPR) spectroscopy. Skeletal myoblast (SM) cells isolated from thigh muscle biopsies of mice were labeled with OxySpin by coculturing the cells with submicron-sized (270 +/- 120 nm) particulates of the probe. Myocardial infarction was created by left coronary artery ligation in mice. Immediately after ligation, labeled SM cells were transplanted in the ischemic region of the heart. The engraftment of the transplanted cells and in situ Po(2) in the heart were monitored weekly for 4 wk. EPR measurements revealed the retention of cells in the infarcted tissue. The myocardial Po(2) at the site of SM cell therapy was significantly higher compared with the untreated group throughout the 4-wk period. Histological studies revealed differentiation and engraftment of SM cells into myotubes and increased incidence of neovascularization in the infarct region. The infarct size in the treated group was significantly decreased, whereas echocardiography showed an overall improvement in cardiac function when compared with untreated hearts. To our knowledge, this the first report detailing changes in in situ oxygenation in cell therapy. The increased myocardial Po(2) positively correlated with neoangiogenesis and cardiac function.
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Affiliation(s)
- Mahmood Khan
- Center for Biomedical Electron Paramagnetic Resonance Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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25
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Sostaric JZ, Pandian RP, Bratasz A, Kuppusamy P. Encapsulation of a highly sensitive EPR active oxygen probe into sonochemically prepared microspheres. J Phys Chem B 2007; 111:3298-303. [PMID: 17388464 PMCID: PMC2533636 DOI: 10.1021/jp0682356] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
High-power ultrasound (20 kHz) was used to encapsulate a solution of perchlorotriphenylmethyl triester (PTM-TE, a stable organic free radical) dissolved in hexamethyldisiloxane (HMDS) into a polymerized shell of bovine serum albumin (BSA). The size distribution of the microspheres was between 0.5 and 3 microm with a maximum at approximately 1.2 microm. The electron paramagnetic resonance spectrum of PTM-TE consists of a single, sharp line which is sensitive to the surrounding concentration of oxygen. It was found that the technique of encapsulating a solution of PTM-TE dissolved in HMDS into the BSA microspheres resulted in an overall loss of EPR signal intensity from the washed suspension of microspheres. However, the encapsulated PTM-TE/HMDS solution remained sensitive to the partial pressure of oxygen in the surrounding environment. The microspheres were found to be useful for determining the partial pressure of oxygen in the muscle and tumor tissue of mice.
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Affiliation(s)
| | | | | | - Periannan Kuppusamy
- Corresponding author. Periannan Kuppusamy, Tel: 614-292-8998; Fax: 614-292-8454; E-mail:
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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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