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Swartz HM, Flood AB. Re-examining What the Results of "a Measurement of Oxygen Level in Tissues" Really Mean. Mol Imaging Biol 2024; 26:391-402. [PMID: 38177616 DOI: 10.1007/s11307-023-01887-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024]
Abstract
Within this special issue, many eminent investigators report on measurements of oxygen (O2) levels in tissues. Given the complexities of spatial and temporal heterogeneities of O2 in tissues and its many sources, this commentary draws attention to what such measurements do and do not actually assess regarding O2 levels in tissues. Given this limitation, it also discusses how these results can be used most effectively. To provide a convenient mechanism to discuss these issues more fully, this analysis focuses on measurements using EPR oximetry, but these considerations apply to all other techniques. The nature of the delivery of O2 to tissues and the mechanisms by which O2 is consumed necessarily result in very different levels of O2 within the volume of each voxel of a measurement. Better spatial resolution cannot fully resolve the problem because the variations include O2 gradients within each cell. Improved resolution of the time-dependent variation in O2 is also very challenging because O2 levels within tissues can have fluctuations of O2 levels in the range of milliseconds, while most methods require longer times to acquire the data from each voxel. Based on these issues, we argue that the values obtained inevitably are complex aggregates of averages of O2 levels across space and time in the tissue. These complexities arise from the complex physiology of tissues and are compounded by the limitations of the technique and its ability to acquire data. However, one often can obtain very meaningful and useful results if these complexities and limitations are taken into account. We illustrate this, using results obtained with in vivo EPR oximetry, especially utilizing its capacity to make repeated measurements to follow changes in O2 levels that occur with interventions and/or over time.
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Affiliation(s)
- Harold M Swartz
- Dept. of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
- Clin-EPR, LLC, Lyme, NH, USA
| | - Ann Barry Flood
- Dept. of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA.
- Clin-EPR, LLC, Lyme, NH, USA.
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Fang C, Xi Y, Epel B, Halpern H, Qiao Z. Directional TV algorithm for fast EPR imaging. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 361:107652. [PMID: 38457937 PMCID: PMC11091491 DOI: 10.1016/j.jmr.2024.107652] [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: 10/16/2023] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/10/2024]
Abstract
Precise radiation guided by oxygen images has demonstrated superiority over the traditional radiation methods. Electron paramagnetic resonance (EPR) imaging has proven to be the most advanced oxygen imaging modality. However, the main drawback of EPR imaging is the long scan time. For each projection, we usually need to collect the projection many times and then average them to achieve high signal-to-noise ratio (SNR). One approach to fast scan is to reduce the repeating time for each projection. While the projections would be noisy and thus the traditional commonly-use filtered backprojection (FBP) algorithm would not be capable of accurately reconstructing images. Optimization-based iterative algorithms may accurately reconstruct images from noisy projections for they may incorporate prior information into optimization models. Based on the total variation (TV) algorithms for EPR imaging, in this work, we propose a directional TV (DTV) algorithm to further improve the reconstruction accuracy. We construct the DTV constrained, data divergence minimization (DTVcDM) model, derive its Chambolle-Pock (CP) solving algorithm, validate the correctness of the whole algorithm, and perform evaluations via simulated and real data. The experimental results show that the DTV algorithm outperforms the existing TV and FBP algorithms in fast EPR imaging. Compared to the standard FBP algorithm, the proposed algorithm may achieve 10 times of acceleration.
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Affiliation(s)
- Chenyun Fang
- School of Computer and Information Technology, Shanxi University, Taiyuan, 030006, Shanxi, China
| | - Yarui Xi
- Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing, 400044, Chongqing, China; The Engineering Research Center of Industrial Computed Tomography Nondestructive Testing, Ministry of Education, Chongqing University, Chongqing, 400044, Chongqing, China
| | - Boris Epel
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA
| | - Howard Halpern
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA
| | - Zhiwei Qiao
- School of Computer and Information Technology, Shanxi University, Taiyuan, 030006, Shanxi, China.
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Xun H, Foppiani JA, Bustos VP, Valentine L, Weidman A, Hernandez Alvarez A, Kinney J, Verbat M, Boustany A, Lee BT, Lin SJ. Women in Plastic Surgery Innovation: A 10-Year Review of Gender Representation in Mammary Device Patents. Ann Plast Surg 2024; 92:S305-S308. [PMID: 38556694 DOI: 10.1097/sap.0000000000003872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
BACKGROUND This study aims to pioneer in evaluating women's representation in plastic surgery innovations, focusing on mammary prosthesis devices' inventorship. Despite growing gender parity in the field, women's involvement in innovation remains underexplored. This is especially crucial, as the predominant recipients of these innovative technologies are women, urging a necessity for broader female engagement in pioneering surgical advancements. METHOD Patents under the "A61F2/12: Mammary prostheses and implants" classification between the dates January 1, 2011, to December 31, 2020, were identified using Google Patents Advanced. Inclusion criteria included patents (not designs) in English and applications (not grants), with no litigation limitations. Data collected included ID, title, assignee (categorized as industry, academic, private, individual), inventors, and dates (priority, filing, and publication). Sex of inventors was identified with the literature validated gender API, with manual resolution of unresolved genders or with ga_accuracy scores of less than 75%. Data were analyzed using 2-tailed Student t tests, χ2 analysis, and Pearson correlation coefficient (significance set at P ≤ 0.05). RESULTS Of the more than 130,000 plastic surgery patents in English identified between the 10-year period, 1355 were classified as A61F2/12. A total of 374 unique patents were included for analysis (841 duplicates were removed, and 140 patents were excluded because of non-English character author names). There was a significant increase in patents over the decade (from 15 in 2011 to 88 in 2020, R2 = 0.74, P < 0.05), with a decrease in number of inventors per patent (R2 = 0.12, P < 0.05). Of the 1102 total inventors, 138 were female (11.2%), with a 4-fold increase in representation over the decade (R2 = 0.58, P < 0.05), including increase in patents filed with a woman first inventor (0%-14.8%). Women were equally likely to be first 3 inventors versus middle to last inventors (12.8% vs 11.1%, respectively). CONCLUSIONS Over a decade, mammary device innovations rose significantly. Although women inventors' representation improved, it remains disproportionate compared with women in residency/practice. Hence, interventions should aim to align inventor representation with training ratios, through institutional optimization, reducing gender segmentation, and enhancing funding opportunities.
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Affiliation(s)
- Helen Xun
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Jose A Foppiani
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Valeria P Bustos
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Lauren Valentine
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Allan Weidman
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Angelica Hernandez Alvarez
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - JacqueLyn Kinney
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Miroslava Verbat
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Ashley Boustany
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Bernard T Lee
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Samuel J Lin
- From the Division of Plastic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
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Feng Y, Tan X, Shi Z, Villamena FA, Zweier JL, Song Y, Liu Y. Trityl Quinodimethane Derivatives as Unimolecular Triple-Function Extracellular EPR Probes for Redox, pH, and Oxygen. Anal Chem 2023; 95:1057-1064. [PMID: 36602544 DOI: 10.1021/acs.analchem.2c03754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy and imaging coupled with the use of suitable probes is a promising tool for assessment of the tumor microenvironment (TME). Measurement of multiple TME parameters by EPR is very desirable but challenging. Herein, we designed and synthesized a class of negative-charged trityl quinodimethane MTPs as unimolecular triple-function extracellular probes for redox, pH, and oxygen (O2) levels. Using the deuterated analogue, dMTP5, which has an optimal pKa as well as high sensitivity to bioreduction and O2, we reasonably evaluated pH effects on efflux of reducing agents from HepG2 cells and cellular O2 consumption.
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Affiliation(s)
- Yalan Feng
- The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin300070, P. R. China
| | - Xiaoli Tan
- The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin300070, P. R. China
| | - Zhaojun Shi
- The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin300070, P. R. China
| | - Frederick A Villamena
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, Ohio43210, United States
| | - Jay L Zweier
- Center for Biomedical EPR Spectroscopy and Imaging, the Division of Cardiovascular Medicine, Department of Internal Medicine, The Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio43210, United States
| | - Yuguang Song
- The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin300070, P. R. China
| | - Yangping Liu
- The province and ministry co-sponsored collaborative innovation center for medical epigenetics, Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin300070, P. R. China
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Gallez B. The Role of Imaging Biomarkers to Guide Pharmacological Interventions Targeting Tumor Hypoxia. Front Pharmacol 2022; 13:853568. [PMID: 35910347 PMCID: PMC9335493 DOI: 10.3389/fphar.2022.853568] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 06/23/2022] [Indexed: 12/12/2022] Open
Abstract
Hypoxia is a common feature of solid tumors that contributes to angiogenesis, invasiveness, metastasis, altered metabolism and genomic instability. As hypoxia is a major actor in tumor progression and resistance to radiotherapy, chemotherapy and immunotherapy, multiple approaches have emerged to target tumor hypoxia. It includes among others pharmacological interventions designed to alleviate tumor hypoxia at the time of radiation therapy, prodrugs that are selectively activated in hypoxic cells or inhibitors of molecular targets involved in hypoxic cell survival (i.e., hypoxia inducible factors HIFs, PI3K/AKT/mTOR pathway, unfolded protein response). While numerous strategies were successful in pre-clinical models, their translation in the clinical practice has been disappointing so far. This therapeutic failure often results from the absence of appropriate stratification of patients that could benefit from targeted interventions. Companion diagnostics may help at different levels of the research and development, and in matching a patient to a specific intervention targeting hypoxia. In this review, we discuss the relative merits of the existing hypoxia biomarkers, their current status and the challenges for their future validation as companion diagnostics adapted to the nature of the intervention.
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Chen EY, Tse D, Hou H, Schreiber WA, Schaner PE, Kmiec MM, Hebert KA, Kuppusamy P, Swartz HM, Williams BB. Evaluation of a Refined Implantable Resonator for Deep-Tissue EPR Oximetry in the Clinic. APPLIED MAGNETIC RESONANCE 2021; 52:1321-1342. [PMID: 34744319 PMCID: PMC8570533 DOI: 10.1007/s00723-021-01376-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 05/04/2023]
Abstract
OBJECTIVES (1) Summarize revisions made to the implantable resonator (IR) design and results of testing to characterize biocompatibility;(2) Demonstrate safety of implantation and feasibility of deep tissue oxygenation measurement using electron paramagnetic resonance (EPR) oximetry. STUDY DESIGN In vitro testing of the revised IR and in vivo implantation in rabbit brain and leg tissues. METHODS Revised IRs were fabricated with 1-4 OxyChips with a thin wire encapsulated with two biocompatible coatings. Biocompatibility and chemical characterization tests were performed. Rabbits were implanted with either an IR with 2 oxygen sensors or a biocompatible-control sample in both the brain and hind leg. The rabbits were implanted with IRs using a catheter-based, minimally invasive surgical procedure. EPR oximetry was performed for rabbits with IRs. Cohorts of rabbits were euthanized and tissues were obtained at 1 week, 3 months, and 9 months after implantation and examined for tissue reaction. RESULTS Biocompatibility and toxicity testing of the revised IRs demonstrated no abnormal reactions. EPR oximetry from brain and leg tissues were successfully executed. Blood work and histopathological evaluations showed no significant difference between the IR and control groups. CONCLUSIONS IRs were functional for up to 9 months after implantation and provided deep tissue oxygen measurements using EPR oximetry. Tissues surrounding the IRs showed no more tissue reaction than tissues surrounding the control samples. This pre-clinical study demonstrates that the IRs can be safely implanted in brain and leg tissues and that repeated, non-invasive, deep-tissue oxygen measurements can be obtained using in vivo EPR oximetry.
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Affiliation(s)
- Eunice Y. Chen
- Section of Otolaryngology, Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Dan Tse
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Huagang Hou
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Wilson A. Schreiber
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Philip E. Schaner
- Section of Radiation Oncology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Maciej M. Kmiec
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Kendra A. Hebert
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Periannan Kuppusamy
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Harold M. Swartz
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
- Section of Radiation Oncology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Benjamin B. Williams
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
- Section of Radiation Oncology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
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Gertsenshteyn I, Giurcanu M, Vaupel P, Halpern H. Biological validation of electron paramagnetic resonance (EPR) image oxygen thresholds in tissue. J Physiol 2021; 599:1759-1767. [PMID: 32506448 PMCID: PMC7719598 DOI: 10.1113/jp278816] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/26/2020] [Indexed: 12/17/2022] Open
Abstract
Measuring molecular oxygen levels in vivo has been the cornerstone of understanding the effects of hypoxia in normal tissues and malignant tumors. Here we discuss the advances in a variety of partial pressure of oxygen ( P O 2 ) measurements and imaging techniques and relevant oxygen thresholds. A focus on electron paramagnetic resonance (EPR) imaging shows the validation of treating hypoxic tumours with a threshold of P O 2 ≤ 10 Torr, and demonstrates utility for in vivo oxygen imaging, as well as its current and future role in cancer studies.
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Affiliation(s)
- Inna Gertsenshteyn
- Department of Radiology, University of Chicago, IL, USA
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, USA
- Center for EPR Imaging In Vivo Physiology, University of Chicago, Chicago, IL, USA
| | - Mihai Giurcanu
- Department of Public Health Sciences, University of Chicago, IL, USA
| | - Peter Vaupel
- Department of Radiation Oncology, Medical Center, University of Freiburg, Germany
- German Cancer Consortium (DKTK), Partner site Freiburg and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Howard Halpern
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, USA
- Center for EPR Imaging In Vivo Physiology, University of Chicago, Chicago, IL, USA
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Tan X, Ji K, Wang X, Yao R, Han G, Villamena FA, Zweier JL, Song Y, Rockenbauer A, Liu Y. Discriminative Detection of Biothiols by Electron Paramagnetic Resonance Spectroscopy using a Methanethiosulfonate Trityl Probe. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201912832] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Xiaoli Tan
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Kaiyun Ji
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Xing Wang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Ru Yao
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Guifang Han
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Frederick A. Villamena
- Department of Biological Chemistry and PharmacologyCollege of MedicineThe Ohio State University Columbus OH 43210 USA
| | - Jay L. Zweier
- Center for Biomedical EPR Spectroscopy and ImagingThe Davis Heart and Lung Research Institutethe Division of Cardiovascular MedicineDepartment of Internal MedicineThe Ohio State University Columbus OH 43210 USA
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
| | - Antal Rockenbauer
- Institute of Materials and Environmental ChemistryResearch Centre for Natural SciencesHungarian Academy of Sciences 1117 Budapest Hungary
- Department of PhysicsBudapest University of Technology and Economics Budafoki ut 8 1111 Budapest Hungary
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and DiagnosticsSchool of PharmacyTianjin Medical University Tianjin 300070 P. R. China
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Clinical and Statistical Considerations when Assessing Oxygen Levels in Tumors: Illustrative Results from Clinical EPR Oximetry Studies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1232:155-168. [PMID: 31893406 DOI: 10.1007/978-3-030-34461-0_20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The success of treatment for malignancies, especially those undergoing radiation therapy or chemotherapy, has long been recognized to depend on the degree of hypoxia in the tumor. In addition to the prognostic value of knowing the tumor's initial level of hypoxia, assessing the tumor oxygenation during standard therapy or oxygen-related treatments (such as breathing oxygen-enriched gas mixtures or taking drugs that can increase oxygen supply to tissues) can provide valuable data to improve the efficacy of treatments. A series of early clinical studies of tumors in humans are ongoing at Dartmouth and Emory using electron paramagnetic resonance (EPR) oximetry to assess tumor oxygenation, initially and over time during either natural disease progression or treatment. This approach has the potential for reaching the long-sought goal of enhancing the effectiveness of cancer therapy. In order to effectively reach this goal, we consider the validity of the practical and statistical assumptions when interpreting the measurements made in vivo for patients undergoing treatment for cancer.
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Tan X, Ji K, Wang X, Yao R, Han G, Villamena FA, Zweier JL, Song Y, Rockenbauer A, Liu Y. Discriminative Detection of Biothiols by Electron Paramagnetic Resonance Spectroscopy using a Methanethiosulfonate Trityl Probe. Angew Chem Int Ed Engl 2019; 59:928-934. [PMID: 31657108 DOI: 10.1002/anie.201912832] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Indexed: 12/30/2022]
Abstract
Biothiols, such as glutathione (GSH), homocysteine (Hcy), and cysteine (Cys), coexist in biological systems with diverse biological roles. Thus, analytical techniques that can detect, quantify, and distinguish between multiple biothiols are desirable but challenging. Herein, we demonstrate the simultaneous detection and quantitation of multiple biothiols, including up to three different biothiols in a single sample, using electron paramagnetic resonance (EPR) spectroscopy and a trityl-radical-based probe (MTST). We term this technique EPR thiol-trapping. MTST could trap thiols through its methanethiosulfonate group to form the corresponding disulfide conjugate with an EPR spectrum characteristic of the trapped thiol. MTST was used to investigate effects of l-buthionine sulfoximine (BSO) and pyrrolidine dithiocarbamate (PDTC) on the efflux of GSH and Cys from HepG2 cells.
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Affiliation(s)
- Xiaoli Tan
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Kaiyun Ji
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Xing Wang
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Ru Yao
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Guifang Han
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Frederick A Villamena
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Jay L Zweier
- Center for Biomedical EPR Spectroscopy and Imaging, The Davis Heart and Lung Research Institute, the Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Yuguang Song
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
| | - Antal Rockenbauer
- Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117, Budapest, Hungary.,Department of Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest, Hungary
| | - Yangping Liu
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, 300070, P. R. China
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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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Desmet CM, Tran LBA, Danhier P, Gallez B. Characterization of a clinically used charcoal suspension for in vivo EPR oximetry. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2018; 32:205-212. [DOI: 10.1007/s10334-018-0704-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/21/2018] [Accepted: 08/31/2018] [Indexed: 12/18/2022]
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Nezakati T, Seifalian A, Tan A, Seifalian AM. Conductive Polymers: Opportunities and Challenges in Biomedical Applications. Chem Rev 2018; 118:6766-6843. [DOI: 10.1021/acs.chemrev.6b00275] [Citation(s) in RCA: 354] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Toktam Nezakati
- Google Inc.., Mountain View, California 94043, United States
- Centre for Nanotechnology and Regenerative Medicine, Division of Surgery and Interventional Science, University College London, London NW3 2QG, United Kingdom
| | - Amelia Seifalian
- UCL Medical School, University College London, London WC1E 6BT, United Kingdom
| | - Aaron Tan
- UCL Medical School, University College London, London WC1E 6BT, United Kingdom
| | - Alexander M. Seifalian
- NanoRegMed Ltd. (Nanotechnology and Regenerative Medicine Commercialization Centre), The London Innovation BioScience Centre, London NW1 0NH, United Kingdom
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Kishimoto S, Matsumoto KI, Saito K, Enomoto A, Matsumoto S, Mitchell JB, Devasahayam N, Krishna MC. Pulsed Electron Paramagnetic Resonance Imaging: Applications in the Studies of Tumor Physiology. Antioxid Redox Signal 2018; 28:1378-1393. [PMID: 29130334 PMCID: PMC5910045 DOI: 10.1089/ars.2017.7391] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SIGNIFICANCE Electron paramagnetic resonance imaging (EPRI) is capable of generating images of tissue oxygenation using exogenous paramagnetic probes such as trityl radicals or nitroxyl radicals. The spatial distribution of the paramagnetic probe can be generated using magnetic field gradients as in magnetic resonance imaging and, from its spectral features, spatial maps of oxygen can be obtained from live objects. In this review, two methods of signal acquisition and image formation/reconstruction are described. The probes used and its application to study tumor physiology and monitor treatment response with chemotherapy drugs in mouse models of human cancer are summarized. Recent Advances: By implementing phase encoding/Fourier reconstruction in EPRI in time domain mode, the frequency contribution to the spatial resolution was avoided and images with improved spatial resolution were obtained. The EPRI-generated pO2 maps in tumor were useful to detect and evaluate the effects of various antitumor therapies on tumor physiology. Coregistration with other imaging modalities provided a better understanding of hypoxia-related alteration in physiology. CRITICAL ISSUES The high radiofrequency (RF) power of EPR irradiation and toxicity profile of radical probes are the main obstacles for clinical application. The improvement of RF low power pulse sequences may allow for clinical translation. FUTURE DIRECTIONS Pulsed EPR oximetry can be a powerful tool to research various diseases involving hypoxia such as cancer, ischemic heart diseases, stroke, and diabetes. With appropriate paramagnetic probes, it can also be applied for various other purposes such as detecting local acid-base balance or oxidative stress. Antioxid. Redox Signal. 28, 1378-1393.
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Affiliation(s)
- Shun Kishimoto
- 1 Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Ken-Ichiro Matsumoto
- 2 Quantitative RedOx Sensing Team, Department of Basic Medical Sciences for Radiation Damages, Chiba, Japan
| | - Keita Saito
- 1 Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Ayano Enomoto
- 1 Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Shingo Matsumoto
- 3 Division of Bioengineering and Bioinformatics, Hokkaido University , Sapporo, Japan
| | - James B Mitchell
- 1 Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Nallathamby Devasahayam
- 1 Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
| | - Murali C Krishna
- 1 Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda, Maryland
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Kishimoto S, Krishna MC, Khramtsov VV, Utsumi H, Lurie DJ. In Vivo Application of Proton-Electron Double-Resonance Imaging. Antioxid Redox Signal 2018; 28:1345-1364. [PMID: 28990406 PMCID: PMC5910041 DOI: 10.1089/ars.2017.7341] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/05/2017] [Indexed: 01/01/2023]
Abstract
SIGNIFICANCE Proton-electron double-resonance imaging (PEDRI) employs electron paramagnetic resonance irradiation with low-field magnetic resonance imaging so that the electron spin polarization is transferred to nearby protons, resulting in higher signals. PEDRI provides information about free radical distribution and, indirectly, about the local microenvironment such as partial pressure of oxygen (pO2), tissue permeability, redox status, and acid-base balance. Recent Advances: Local acid-base balance can be imaged by exploiting the different resonance frequency of radical probes between R and RH+ forms. Redox status can also be imaged by using the loss of radical-related signal after reduction. These methods require optimized radical probes and pulse sequences. CRITICAL ISSUES High-power radio frequency irradiation is needed for optimum signal enhancement, which may be harmful to living tissue by unwanted heat deposition. Free radical probes differ depending on the purpose of PEDRI. Some probes are less effective for enhancing signal than others, which can reduce image quality. It is so far not possible to image endogenous radicals by PEDRI because low concentrations and broad line widths of the radicals lead to negligible signal enhancement. FUTURE DIRECTIONS PEDRI has similarities with electron paramagnetic resonance imaging (EPRI) because both techniques observe the EPR signal, directly in the case of EPRI and indirectly with PEDRI. PEDRI provides information that is vital to research on homeostasis, development of diseases, or treatment responses in vivo. It is expected that the development of new EPR techniques will give insights into novel PEDRI applications and vice versa. Antioxid. Redox Signal. 28, 1345-1364.
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Affiliation(s)
- Shun Kishimoto
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Murali C. Krishna
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Valery V. Khramtsov
- In Vivo Multifunctional Magnetic Resonance center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia
- Department of Biochemistry, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia
| | - Hideo Utsumi
- School of Pharmaceutical Sciences, The University of Shizuoka, Shizuoka, Japan
| | - David J. Lurie
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
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16
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Turin L, Skoulakis EM. Electron Spin Resonance (EPR) in Drosophila and General Anesthesia. Methods Enzymol 2018; 603:115-128. [DOI: 10.1016/bs.mie.2018.01.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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17
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Gallez B, Neveu MA, Danhier P, Jordan BF. Manipulation of tumor oxygenation and radiosensitivity through modification of cell respiration. A critical review of approaches and imaging biomarkers for therapeutic guidance. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:700-711. [DOI: 10.1016/j.bbabio.2017.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 11/17/2022]
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18
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Hou H, Khan N, Gohain S, Eskey CJ, Moodie KL, Maurer KJ, Swartz HM, Kuppusamy P. Dynamic EPR Oximetry of Changes in Intracerebral Oxygen Tension During Induced Thromboembolism. Cell Biochem Biophys 2017; 75:285-294. [PMID: 28434138 DOI: 10.1007/s12013-017-0798-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/12/2017] [Indexed: 12/19/2022]
Abstract
Cerebral tissue oxygenation (oxygen tension, pO2) is a critical parameter that is closely linked to brain metabolism, function, and pathophysiology. In this work, we have used electron paramagnetic resonance oximetry with a deep-tissue multi-site oxygen-sensing probe, called implantable resonator, to monitor temporal changes in cerebral pO2 simultaneously at four sites in a rabbit model of ischemic stroke induced by embolic clot. The pO2 values in healthy brain were not significantly different among the four sites measured over a period of 4 weeks. During exposure to 15% O2 (hypoxia), a sudden and significant decrease in pO2 was observed in all four sites. On the other hand, brief exposure to breathing carbogen gas (95% O2 + 5% CO2) showed a significant increase in the cerebral pO2 from baseline value. During ischemic stroke, induced by embolic clot in the left brain, a significant decline in the pO2 of the left cortex (ischemic core) was observed without any change in the contralateral sites. While the pO2 in the non-infarct regions returned to baseline at 24-h post-stroke, pO2 in the infarct core was consistently lower compared to the baseline and other regions of the brain. The results demonstrated that electron paramagnetic resonance oximetry with the implantable resonator can repeatedly and simultaneously report temporal changes in cerebral pO2 at multiple sites. This oximetry approach can be used to develop interventions to rescue hypoxic/ischemic tissue by modulating cerebral pO2 during hypoxic and stroke injury.
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Affiliation(s)
- Huagang Hou
- Department of Radiology, The Geisel School of Medicine, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA
| | - Nadeem Khan
- Department of Radiology, The Geisel School of Medicine, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA
| | - Sangeeta Gohain
- Department of Radiology, The Geisel School of Medicine, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA
| | - Clifford J Eskey
- Department of Radiology, The Geisel School of Medicine, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA
| | - Karen L Moodie
- Center for Comparative Medicine and Research, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA
| | - Kirk J Maurer
- Center for Comparative Medicine and Research, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA
| | - Harold M Swartz
- Department of Radiology, The Geisel School of Medicine, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA
| | - Periannan Kuppusamy
- Department of Radiology, The Geisel School of Medicine, Dartmouth College, 1 Medical Center Drive,, Lebanon, 03756, NH, USA.
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Swartz HM. Using Stable Free Radicals to Obtain Unique and Clinically Useful Data In Vivo in Human Subjects. RADIATION PROTECTION DOSIMETRY 2016; 172:3-15. [PMID: 27886997 PMCID: PMC6061194 DOI: 10.1093/rpd/ncw323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/30/2016] [Indexed: 06/06/2023]
Abstract
This paper attempts to: (1) provide a critical overview of the challenges and opportunities to extend electron paramagnetic resonance (EPR) into practical applications in human subjects, based on EPR measurements made in vivo; (2) summarize the clinical applications of EPR for improving treatments in cancer, wound healing and diabetic care, emphasizing EPR's unique capability to measure tissue oxygen repeatedly and with particular sensitivity to hypoxia and (3) summarize the capabilities of in vivo EPR to measure radiation dose for triage and medical guidance after a large-scale radiation exposure. The conclusion is that while still at a relatively early stage of its development and availability, clinical applications of EPR already have demonstrated significant value and the field is likely to grow in both the extent of its applications and its impact on significant problems.
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Affiliation(s)
- Harold M Swartz
- EPR Center for the Study of Viable Systems at Dartmouth, Department of Radiology, Geisel School of Medicine at Dartmouth, HB 7785 One Medical Center Drive, Lebanon, NH 03756, USA
- Division of Radiation Oncology, Department of Medicine, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA
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20
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Gallez B. Contribution of Harold M. Swartz to In Vivo EPR and EPR Dosimetry. RADIATION PROTECTION DOSIMETRY 2016; 172:16-37. [PMID: 27421469 DOI: 10.1093/rpd/ncw157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In 2015, we are celebrating half a century of research in the application of Electron Paramagnetic Resonance (EPR) as a biodosimetry tool to evaluate the dose received by irradiated people. During the EPR Biodose 2015 meeting, a special session was organized to acknowledge the pioneering contribution of Harold M. (Hal) Swartz in the field. The article summarizes his main contribution in physiology and medicine. Four emerging themes have been pursued continuously along his career since its beginning: (1) radiation biology; (2) oxygen and oxidation; (3) measuring physiology in vivo; and (4) application of these measurements in clinical medicine. The common feature among all these different subjects has been the use of magnetic resonance techniques, especially EPR. In this article, you will find an impressionist portrait of Hal Swartz with the description of the 'making of' this pioneer, a time-line perspective on his career with the creation of three National Institutes of Health-funded EPR centers, a topic-oriented perspective on his career with a description of his major contributions to Science, his role as a mentor and his influence on his academic children, his active role as founder of scientific societies and organizer of scientific meetings, and the well-deserved international recognition received so far.
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Affiliation(s)
- Bernard Gallez
- Université Catholique de Louvain, Louvain Drug Research Institute, Biomedical Magnetic Resonance Research Group, Avenue Mounier 73.08, B-1200, Brussels, Belgium
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21
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Melnikov AR, Verkhovlyuk VN, Kalneus EV, Korolev VV, Borovkov VI, Sherin PS, Davydova MP, Vasilevsky SF, Stass DV. Estimation of the Fraction of Spin-Correlated Radical Ion Pairs in Irradiated Alkanes using Magnetosensitive Recombination Luminescence from Exciplexes Generated upon Recombination of a Probe Pair. ACTA ACUST UNITED AC 2016. [DOI: 10.1515/zpch-2016-0819] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
We suggest a convenient probe exciplex system for studies in radiation spin chemistry based on a novel acceptor-substituted diphenylacetylene, 1-(phenylethynyl)-4-(trifluoromethyl)benzene that has a very short fluorescence lifetime (<200 ps) and low quantum yield (0.01) of intrinsic emission, provides efficient electron capture in alkanes and efficient exciplex formation upon recombination in pair with DMA radical cation, while exhibiting a shifted to red exciplex emission band as compared to the parent system DMA – diphenylacetylene. After chemical, luminescent, radiation and spin-chemical characterization of the new system we used the magnitude of magnetic field effect in its exciplex emission band for experimental estimation of the fraction of spin-correlated radical ion pairs under X-irradiation with upper energy cutoff 40 keV in a set of 11 alkanes. For linear and branched alkanes magnetic field effects and the corresponding fractions are approximately 19–20% and 0.28, while for cyclic alkanes they are lower at 16–17% and 0.22, respectively.
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Affiliation(s)
- Anatoly R. Melnikov
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090 Novosibirsk, Russian Federation
- Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation
| | - Vladimir N. Verkhovlyuk
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090 Novosibirsk, Russian Federation
| | - Evgeny V. Kalneus
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090 Novosibirsk, Russian Federation
| | - Valeri V. Korolev
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090 Novosibirsk, Russian Federation
| | - Vsevolod I. Borovkov
- Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090, Russian Federation
| | - Peter S. Sherin
- Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation
- International Tomography Center SB RAS, 3a, Institutskaya Str., 630090 Novosibirsk, Russian Federation
| | - Maria P. Davydova
- Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090, Russian Federation
| | - Sergei F. Vasilevsky
- Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090, Russian Federation
| | - Dmitri V. Stass
- Novosibirsk State University, 2, Pirogova Str., 630090 Novosibirsk, Russian Federation
- Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 3, Institutskaya Str., 630090, Russian Federation
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Wen T, Wamer WG, Subczynski WK, Hou S, Wu X, Yin JJ. Enhancement of Paramagnetic Relaxation by Photoexcited Gold Nanorods. Sci Rep 2016; 6:24101. [PMID: 27071507 PMCID: PMC4829829 DOI: 10.1038/srep24101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 03/21/2016] [Indexed: 12/05/2022] Open
Abstract
Electron spin resonance (ESR) spectroscopy was used to investigate the switchable, light-dependent effects of gold nanorods (GNRs) on paramagnetic properties of nitroxide spin probes. The photoexcited GNRs enhanced the spin-spin and spin-lattice relaxations of nitroxide spin probes. It was shown that molecular oxygen plays the key role in this process. Our results demonstrate that ESR is a powerful tool for investigating the events following photoexcitation of GNRs. The novel light-controlled effects observed for GNRs on paramagnetic properties and activities of surrounding molecules have a number of significant applications where oxygen sensing and oxygen activity is important.
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Affiliation(s)
- Tao Wen
- Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park 20740, MD, USA
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
- Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, P. R. China
| | - Wayne G. Wamer
- Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park 20740 MD, USA
| | | | - Shuai Hou
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Xiaochun Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, P. R. China
| | - Jun-Jie Yin
- Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, College Park 20740, MD, USA
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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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Epel B, Halpern HJ. In Vivo pO2 Imaging of Tumors: Oxymetry with Very Low-Frequency Electron Paramagnetic Resonance. Methods Enzymol 2015; 564:501-27. [PMID: 26477263 DOI: 10.1016/bs.mie.2015.08.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
For over a century, it has been known that tumor hypoxia, regions of a tumor with low levels of oxygenation, are important contributors to tumor resistance to radiation therapy and failure of radiation treatment of cancer. Recently, using novel pulse electron paramagnetic resonance (EPR) oxygen imaging, near absolute images of the partial pressure of oxygen (pO2) in tumors of living animals have been obtained. We discuss here the means by which EPR signals can be obtained in living tissues and tumors. We review development of EPR methods to image the pO2 in tumors and the potential for the pO2 image acquisition in human subjects.
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Affiliation(s)
- Boris Epel
- Center for Electron Paramagnetic Resonance Imaging In Vivo Physiology, Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois, USA
| | - Howard J Halpern
- Center for Electron Paramagnetic Resonance Imaging In Vivo Physiology, Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois, USA.
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25
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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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26
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Hashem M, Weiler-Sagie M, Kuppusamy P, Neufeld G, Neeman M, Blank A. Electron spin resonance microscopic imaging of oxygen concentration in cancer spheroids. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 256:77-85. [PMID: 26022394 DOI: 10.1016/j.jmr.2015.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 06/04/2023]
Abstract
Oxygen (O2) plays a central role in most living organisms. The concentration of O2 is important in physiology and pathology. Despite the importance of accurate knowledge of the O2 levels, there is very limited capability to measure with high spatial resolution its distribution in millimeter-scale live biological samples. Many of the current oximetric methods, such as oxygen microelectrodes and fluorescence lifetime imaging, are compromised by O2 consumption, sample destruction, invasiveness, and difficulty to calibrate. Here, we present a new method, based on the use of the pulsed electron spin resonance (ESR) microimaging technique to obtain a 3D mapping of oxygen concentration in millimeter-scale biological samples. ESR imaging requires the incorporation of a suitable stable and inert paramagnetic spin probe into the desirable object. In this work, we use microcrystals of a paramagnetic spin probe in a new crystallographic packing form (denoted tg-LiNc-BuO). These paramagnetic species interact with paramagnetic oxygen molecules, causing a spectral line broadening that is linearly proportional to the oxygen concentration. Typical ESR results include 4D spatial-spectral images that give an indication about the oxygen concentration in different regions of the sample. This new oximetry microimaging method addresses all the problems mentioned above. It is noninvasive, sensitive to physiological oxygen levels, and easy to calibrate. Furthermore, in principle, it can be used for repetitive measurements without causing cell damage. The tissue model used in this research is spheroids of Human Colorectal carcinoma cell line (HCT-116) with a typical diameter of ∼600μm. Most studies of the microenvironmental O2 conditions inside such viable spheroids carried out in the past used microelectrodes, which require an invasive puncturing of the spheroid and are also not applicable to 3D O2 imaging. High resolution 3D oxygen maps could make it possible to evaluate the relationship between morphological and physiological alterations in the spheroids, which would help understand the oxygen metabolism in solid tumors and its correlation with the susceptibility of tumors to various oncologic treatments.
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Affiliation(s)
- Mada Hashem
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Michal Weiler-Sagie
- Department of Biological Regulation - Weizmann Institute of Science, Rehovot, Israel
| | - Periannan Kuppusamy
- EPR Center for Viable Systems and the Geisel School of Medicine at Dartmouth, Departments of Radiology and Medicine, Lebanon, NH 03766, USA
| | - Gera Neufeld
- The Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Michal Neeman
- Department of Biological Regulation - Weizmann Institute of Science, Rehovot, Israel
| | - Aharon Blank
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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Frank J, Elewa M, Said MM, El Shihawy HA, El-Sadek M, Müller D, Meister A, Hause G, Drescher S, Metz H, Imming P, Mäder K. Synthesis, Characterization, and Nanoencapsulation of Tetrathiatriarylmethyl and Tetrachlorotriarylmethyl (Trityl) Radical Derivatives—A Study To Advance Their Applicability as in Vivo EPR Oxygen Sensors. J Org Chem 2015; 80:6754-66. [PMID: 26020133 DOI: 10.1021/acs.joc.5b00918] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tissue oxygenation plays an important role in the pathophysiology of various diseases and is often a marker of prognosis and therapeutic response. EPR (ESR) is a suitable noninvasive oximetry technique. However, to reliably deploy soluble EPR probes as oxygen sensors in complex biological systems, there is still a need to investigate and improve their specificity, sensitivity, and stability. We reproducibly synthesized various derivatives of tetrathiatriarylmethyl and tetrachlorotriarylmethyl (trityl) radicals. Hydrophilic radicals were investigated in aqueous solution mimicking physiological conditions by, e.g., variation of viscosity and ionic strength. Their specificity was satisfactory, but the oxygen sensitivity was low. To enhance the capability of trityl radicals as oxygen sensors, encapsulation into oily core nanocapsules was performed. Thus, different lipophilic triesters were prepared and characterized in oily solution employing oils typically used in drug formulations, i.e., middle-chain triglycerides and isopropyl myristate. Our screening identified the deuterated ethyl ester of D-TAM (radical 13) to be suitable. It had an extremely narrow single EPR line under anoxic conditions and excellent oxygen sensitivity. After encapsulation, it retained its oxygen responsiveness and was protected against reduction by ascorbic acid. These biocompatible and highly sensitive nanosensors offer great potential for future EPR oximetry applications in preclinical research.
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Affiliation(s)
- Juliane Frank
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Marwa Elewa
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany.,‡Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | - Mohamed M Said
- ‡Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | - Hosam A El Shihawy
- ‡Faculty of Pharmacy, Suez Canal University, P.O. 41522, Ismailia, Egypt
| | | | - Diana Müller
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Annette Meister
- ⊥Center for Structure and Dynamics of Proteins (MZP), Biocenter Martin-Luther-Universität (MLU) Halle-Wittenberg, Weinbergweg 22, 06120 Halle (Saale), Germany
| | - Gerd Hause
- #Biocenter Martin-Luther-Universität (MLU) Halle-Wittenberg, Weinbergweg 22, 06120 Halle (Saale), Germany
| | - Simon Drescher
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Hendrik Metz
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Peter Imming
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
| | - Karsten Mäder
- †Institut für Pharmazie, Martin-Luther-Universität (MLU) Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle (Saale), Germany
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28
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Wei M, Wan J, Hu Z, Wang B, Peng Z. Synthesis, electron transfer and photocatalytic activity of TiO2 nanotubes sensitized by meso-tetra(4-carboxyphenyl)porphyrin under visible-light irradiation. RSC Adv 2015. [DOI: 10.1039/c5ra11526d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Porphyrin plays a crucial role in the process of photocatalysis, porphyrin compounds are naturally suitable antennas for solar energy collection and promising direct solar energy-to-chemical conversion equipment.
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Affiliation(s)
- Meng Wei
- State Key Laboratory of Advanced Textiles Materials and Manufacture Technology (MOE)
- Zhejiang Sci-Tech University
- Hangzhou
- China
| | - Junmin Wan
- State Key Laboratory of Advanced Textiles Materials and Manufacture Technology (MOE)
- Zhejiang Sci-Tech University
- Hangzhou
- China
| | - Zhiwen Hu
- State Key Laboratory of Advanced Textiles Materials and Manufacture Technology (MOE)
- Zhejiang Sci-Tech University
- Hangzhou
- China
| | - Bing Wang
- State Key Laboratory of Advanced Textiles Materials and Manufacture Technology (MOE)
- Zhejiang Sci-Tech University
- Hangzhou
- China
| | - Zhiqin Peng
- State Key Laboratory of Advanced Textiles Materials and Manufacture Technology (MOE)
- Zhejiang Sci-Tech University
- Hangzhou
- China
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29
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Jagtap AP, Krstic I, Kunjir NC, Hänsel R, Prisner TF, Sigurdsson ST. Sterically shielded spin labels for in-cell EPR spectroscopy: Analysis of stability in reducing environment. Free Radic Res 2014; 49:78-85. [DOI: 10.3109/10715762.2014.979409] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Danhier P, Gallez B. Electron paramagnetic resonance: a powerful tool to support magnetic resonance imaging research. CONTRAST MEDIA & MOLECULAR IMAGING 2014; 10:266-81. [PMID: 25362845 DOI: 10.1002/cmmi.1630] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/18/2014] [Indexed: 12/31/2022]
Abstract
The purpose of this paper is to describe some of the areas where electron paramagnetic resonance (EPR) has provided unique information to MRI developments. The field of application mainly encompasses the EPR characterization of MRI paramagnetic contrast agents (gadolinium and manganese chelates, nitroxides) and superparamagnetic agents (iron oxide particles). The combined use of MRI and EPR has also been used to qualify or disqualify sources of contrast in MRI. Illustrative examples are presented with attempts to qualify oxygen sensitive contrast (i.e. T1 - and T2 *-based methods), redox status or melanin content in tissues. Other areas are likely to benefit from the combined EPR/MRI approach, namely cell tracking studies. Finally, the combination of EPR and MRI studies on the same models provides invaluable data regarding tissue oxygenation, hemodynamics and energetics. Our description will be illustrative rather than exhaustive to give to the readers a flavour of 'what EPR can do for MRI'.
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Affiliation(s)
- Pierre Danhier
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Bernard Gallez
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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31
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Albenberg L, Esipova TV, Judge CP, Bittinger K, Chen J, Laughlin A, Grunberg S, Baldassano RN, Lewis JD, Li H, Thom SR, Bushman FD, Vinogradov SA, Wu GD. Correlation between intraluminal oxygen gradient and radial partitioning of intestinal microbiota. Gastroenterology 2014; 147:1055-63.e8. [PMID: 25046162 PMCID: PMC4252572 DOI: 10.1053/j.gastro.2014.07.020] [Citation(s) in RCA: 566] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 06/26/2014] [Accepted: 07/15/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS The gut microbiota is a complex and densely populated community in a dynamic environment determined by host physiology. We investigated how intestinal oxygen levels affect the composition of the fecal and mucosally adherent microbiota. METHODS We used the phosphorescence quenching method and a specially designed intraluminal oxygen probe to dynamically quantify gut luminal oxygen levels in mice. 16S ribosomal RNA gene sequencing was used to characterize the microbiota in intestines of mice exposed to hyperbaric oxygen, human rectal biopsy and mucosal swab samples, and paired human stool samples. RESULTS Average Po2 values in the lumen of the cecum were extremely low (<1 mm Hg). In altering oxygenation of mouse intestines, we observed that oxygen diffused from intestinal tissue and established a radial gradient that extended from the tissue interface into the lumen. Increasing tissue oxygenation with hyperbaric oxygen altered the composition of the gut microbiota in mice. In human beings, 16S ribosomal RNA gene analyses showed an increased proportion of oxygen-tolerant organisms of the Proteobacteria and Actinobacteria phyla associated with rectal mucosa, compared with feces. A consortium of asaccharolytic bacteria of the Firmicute and Bacteroidetes phyla, which primarily metabolize peptones and amino acids, was associated primarily with mucus. This could be owing to the presence of proteinaceous substrates provided by mucus and the shedding of the intestinal epithelium. CONCLUSIONS In an analysis of intestinal microbiota of mice and human beings, we observed a radial gradient of microbes linked to the distribution of oxygen and nutrients provided by host tissue.
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Affiliation(s)
- L Albenberg
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - TV Esipova
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - CP Judge
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - K Bittinger
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - J Chen
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - A Laughlin
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - S Grunberg
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - RN Baldassano
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - JD Lewis
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104,Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - H Li
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - SR Thom
- Dept. of Emergency Medicine, University of Maryland, Baltimore, MD 21201
| | - FD Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - SA Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104,Correspondence: Gary D, Wu, MD, 915 BRB II/III, 421 Curie Blvd, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, Tel: 215-898-0158, Fax: 215-573-2024, , Sergei A. Vinogradov, PhD, 1013 Stellar-Chance Bldg., 422 Curie Blvd., Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, Tel: 215-573-7524,
| | - GD Wu
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104,Correspondence: Gary D, Wu, MD, 915 BRB II/III, 421 Curie Blvd, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, Tel: 215-898-0158, Fax: 215-573-2024, , Sergei A. Vinogradov, PhD, 1013 Stellar-Chance Bldg., 422 Curie Blvd., Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, Tel: 215-573-7524,
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Krzykawska-Serda M, Dąbrowski JM, Arnaut LG, Szczygieł M, Urbańska K, Stochel G, Elas M. The role of strong hypoxia in tumors after treatment in the outcome of bacteriochlorin-based photodynamic therapy. Free Radic Biol Med 2014; 73:239-51. [PMID: 24835769 DOI: 10.1016/j.freeradbiomed.2014.05.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 05/02/2014] [Accepted: 05/02/2014] [Indexed: 12/22/2022]
Abstract
Blood flow and pO2 changes after vascular-targeted photodynamic therapy (V-PDT) or cellular-targeted PDT (C-PDT) using 5,10,15,20-tetrakis(2,6-difluoro-3-N-methylsulfamoylphenyl) bacteriochlorin (F2BMet) as photosensitizer were investigated in DBA/2 mice with S91 Cloudman mouse melanoma, and correlated with long-term tumor responses. F2BMet generates both singlet oxygen and hydroxyl radicals under near-infrared radiation, which consume oxygen. Partial oxygen pressure was lowered in PDT-treated tumors and this was ascribed both to oxygen consumption during PDT and to fluctuations in oxygen transport after PDT. Similarly, microcirculatory blood flow changed as a result of the disruption of blood vessels by the treatment. A novel noninvasive approach combining electron paramagnetic resonance oximetry and laser Doppler blood perfusion measurements allowed longitudinal monitoring of hypoxia and vascular function changes in the same animals, after PDT. C-PDT induced parallel changes in tumor pO2 and blood flow, i.e., an initial decrease immediately after treatment, followed by a slow increase. In contrast, V-PDT led to a strong and persistent depletion of pO2, although the microcirculatory blood flow increased. Strong hypoxia after V-PDT led to a slight increase in VEGF level 24h after treatment. C-PDT caused a ca. 5-day delay in tumor growth, whereas V-PDT was much more efficient and led to tumor growth inhibition in 90% of animals. The tumors of 44% of mice treated with V-PDT regressed completely and did not reappear for over 1 year. In conclusion, mild and transient hypoxia after C-PDT led to intense pO2 compensatory effects and modest tumor inhibition, but strong and persistent local hypoxia after V-PDT caused tumor growth inhibition.
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Affiliation(s)
- Martyna Krzykawska-Serda
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | | | - Luis G Arnaut
- Chemistry Department, University of Coimbra, 3004-535 Coimbra, Portugal; Luzitin SA, 3045-016 Coimbra, Portugal.
| | - Małgorzata Szczygieł
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Krystyna Urbańska
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Grażyna Stochel
- Faculty of Chemistry, Jagiellonian University, 30-060 Krakow, Poland
| | - Martyna Elas
- Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland.
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33
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Ingram J, Zhang C, Cressman JR, Hazra A, Wei Y, Koo YE, Žiburkus J, Kopelman R, Xu J, Schiff SJ. Oxygen and seizure dynamics: I. Experiments. J Neurophysiol 2014; 112:205-12. [PMID: 24598521 DOI: 10.1152/jn.00540.2013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We utilized a novel ratiometric nanoquantum dot fluorescence resonance energy transfer (NQD-FRET) optical sensor to quantitatively measure oxygen dynamics from single cell microdomains during hypoxic episodes as well as during 4-aminopyridine (4-AP)-induced spontaneous seizure-like events in rat hippocampal slices. Coupling oxygen sensing with electrical recordings, we found the greatest reduction in the O2 concentration ([O2]) in the densely packed cell body stratum (st.) pyramidale layer of the CA1 and differential layer-specific O2 dynamics between the st. pyramidale and st. oriens layers. These hypoxic decrements occurred up to several seconds before seizure onset could be electrically measured extracellularly. Without 4-AP, we quantified a narrow range of [O2], similar to the endogenous hypoxia found before epileptiform activity, which permits a quiescent network to enter into a seizure-like state. We demonstrated layer-specific patterns of O2 utilization accompanying layer-specific neuronal interplay in seizure. None of the oxygen overshoot artifacts seen with polarographic measurement techniques were observed. We therefore conclude that endogenously generated hypoxia may be more than just a consequence of increased cellular excitability but an influential and critical factor for orchestrating network dynamics associated with epileptiform activity.
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Affiliation(s)
- Justin Ingram
- Center for Neural Engineering, The Pennsylvania State University, University Park, Pennsylvania; Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania
| | - Chunfeng Zhang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania; Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, China
| | - John R Cressman
- Department of Physics, Astronomy, and Computational Sciences, George Mason University, Fairfax, Virginia
| | - Anupam Hazra
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
| | - Yina Wei
- Center for Neural Engineering, The Pennsylvania State University, University Park, Pennsylvania; Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania
| | - Yong-Eun Koo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan; and
| | - Jokūbas Žiburkus
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
| | - Raoul Kopelman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan; and
| | - Jian Xu
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania
| | - Steven J Schiff
- Center for Neural Engineering, The Pennsylvania State University, University Park, Pennsylvania; Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania; Departments of Neurosurgery and Physics, The Pennsylvania State University, University Park, Pennsylvania
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Hou H, Li H, Dong R, Khan N, Swartz H. Real-time monitoring of ischemic and contralateral brain pO2 during stroke by variable length multisite resonators. Magn Reson Imaging 2014; 32:563-9. [PMID: 24629514 DOI: 10.1016/j.mri.2014.02.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/17/2013] [Accepted: 02/03/2014] [Indexed: 11/19/2022]
Abstract
PURPOSE Electron paramagnetic resonance (EPR) oximetry using variable length multi-probe implantable resonator (IR), was used to investigate the temporal changes in the ischemic and contralateral brain pO2 during stroke in rats. MATERIAL AND METHODS The EPR signal to noise ratio (S/N) of the IR with four sensor loops at a depth of up to 11 mm were compared with direct implantation of lithium phthalocyanine (LiPc, oximetry probe) deposits in vitro. These IRs were used to follow the temporal changes in pO2 at two sites in each hemisphere during ischemia induced by left middle cerebral artery occlusion (MCAO) in rats breathing 30% O2 or 100% O2. RESULTS The S/N ratios of the IRs were significantly greater than the LiPc deposits. A similar pO2 at two sites in each hemisphere prior to the onset of ischemia was observed in rats breathing 30% O2. However, a significant decline in the pO2 of the left cortex and striatum occurred during ischemia, but no change in the pO2 of the contralateral brain was observed. A significant increase in the pO2 of only the contralateral non-ischemic brain was observed in the rats breathing 100% O2. No significant difference in the infarct volume was evident between the animals breathing 30% O2 or 100% O2 during ischemia. CONCLUSIONS EPR oximetry with IRs can repeatedly assess temporal changes in the brain pO2 at four sites simultaneously during stroke. This oximetry approach can be used to test and develop interventions to rescue ischemic tissue by modulating cerebral pO2 during stroke.
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Affiliation(s)
- Huagang Hou
- EPR Center for Viable Systems, Department of Diagnostic Radiology, The Geisel School of Medicine, 48 Lafayette Street, Lebanon, NH 03766; Norris Cotton Cancer Center, One Medical Center Drive, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
| | - Hongbin Li
- EPR Center for Viable Systems, Department of Diagnostic Radiology, The Geisel School of Medicine, 48 Lafayette Street, Lebanon, NH 03766; Norris Cotton Cancer Center, One Medical Center Drive, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - Ruhong Dong
- EPR Center for Viable Systems, Department of Diagnostic Radiology, The Geisel School of Medicine, 48 Lafayette Street, Lebanon, NH 03766; Norris Cotton Cancer Center, One Medical Center Drive, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - Nadeem Khan
- EPR Center for Viable Systems, Department of Diagnostic Radiology, The Geisel School of Medicine, 48 Lafayette Street, Lebanon, NH 03766; Norris Cotton Cancer Center, One Medical Center Drive, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
| | - Harold Swartz
- EPR Center for Viable Systems, Department of Diagnostic Radiology, The Geisel School of Medicine, 48 Lafayette Street, Lebanon, NH 03766; Norris Cotton Cancer Center, One Medical Center Drive, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA
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35
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Functional Imaging of Cerebral Oxygenation with Intrinsic Optical Contrast and Phosphorescent Probes. NEUROMETHODS 2014. [DOI: 10.1007/978-1-62703-785-3_14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Epel B, Redler G, Halpern HJ. How in vivo EPR measures and images oxygen. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 812:113-119. [PMID: 24729222 DOI: 10.1007/978-1-4939-0620-8_15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The partial pressure of oxygen (pO₂) in tissues plays an important role in the pathophysiology of many diseases and influences outcome of cancer therapy, ischemic heart and cerebrovascular disease treatments and wound healing. Over the years a suite of EPR techniques for reliable oxygen measurements has been developed. This is a mini-review of pulse EPR in vivo oxygen imaging methods that utilize soluble spin probes. Recent developments in pulse EPR imaging technology have brought an order of magnitude increase in image acquisition speed, enhancement of sensitivity and considerable improvement in the precision and accuracy of oxygen measurements.
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Affiliation(s)
- Boris Epel
- Center for EPR Imaging In Vivo Physiology, Chicago, IL, USA.,Department of Radiation Oncology, University of Chicago, Chicago, IL, USA
| | - Gage Redler
- Center for EPR Imaging In Vivo Physiology, Chicago, IL, USA.,Department of Radiation Oncology, University of Chicago, Chicago, IL, USA
| | - Howard J Halpern
- Center for EPR Imaging In Vivo Physiology, Chicago, IL, USA. .,Department of Radiation Oncology, University of Chicago, Chicago, IL, USA. .,MC1105, Department of Radiation and Cellular Oncology, University of Chicago Medical Center, 5841 S. Maryland Ave, Chicago, IL, 60637, USA.
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37
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Ingram JM, Zhang C, Xu J, Schiff SJ. FRET excited ratiometric oxygen sensing in living tissue. J Neurosci Methods 2013; 214:45-51. [PMID: 23333398 DOI: 10.1016/j.jneumeth.2013.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 01/03/2013] [Accepted: 01/05/2013] [Indexed: 12/26/2022]
Abstract
Dynamic analysis of oxygen (O₂) has been limited by the lack of a real-time, quantitative, and biocompatible sensor. To address these demands, we designed a ratiometric optode matrix consisting of the phosphorescence quenching dye platinum (II) octaethylporphine ketone (PtOEPK) and nanocystal quantum dots (NQDs), which when embedded within an inert polymer matrix allows long-term pre-designed excitation through fluorescence resonance energy transfer (FRET). Depositing this matrix on various glass substrates allowed the development of a series of optical sensors able to measure interstitial oxygen concentration [O₂] with several hundred millisecond temporal resolution in varying biological microdomains of active brain tissue.
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Affiliation(s)
- Justin M Ingram
- Center for Neural Engineering, Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA, USA.
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38
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Epel, B, Halpern H. Electron paramagnetic resonance oxygen imaging in vivo. ELECTRON PARAMAGNETIC RESONANCE 2012. [DOI: 10.1039/9781849734837-00180] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This review covers the last 15 years of the development of EPR in vivo oxygen imaging. During this time, a number of major technological and methodological advances have taken place. Narrow line width, long relaxation time, and non-toxic triaryl methyl radicals were introduced in the late 1990s. These not only improved continuous wave (CW) imaging, but also enabled the application of pulse EPR imaging to animals. Recent developments in pulse technology have brought an order of magnitude increase in image acquisition speed, enhancement of sensitivity, and considerable improvement in the precision and accuracy of oxygen measurements. Consequently, pulse methods take up a significant part of this review.
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Affiliation(s)
- Boris Epel,
- Center for EPR Imaging in vivo Physiology the University of Chicago, Department of Radiation and Cellular Oncology (MC 1105), Chicago Illinois 60637
| | - Howard Halpern
- Center for EPR Imaging in vivo Physiology the University of Chicago, Department of Radiation and Cellular Oncology (MC 1105), Chicago Illinois 60637
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Yin JJ, Liu J, Ehrenshaft M, Roberts JE, Fu PP, Mason RP, Zhao B. Phototoxicity of nano titanium dioxides in HaCaT keratinocytes--generation of reactive oxygen species and cell damage. Toxicol Appl Pharmacol 2012; 263:81-8. [PMID: 22705594 PMCID: PMC3407290 DOI: 10.1016/j.taap.2012.06.001] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/25/2012] [Accepted: 06/04/2012] [Indexed: 02/03/2023]
Abstract
Nano-sized titanium dioxide (TiO(2)) is among the top five widely used nanomaterials for various applications. In this study, we determine the phototoxicity of TiO(2) nanoparticles (nano-TiO(2)) with different molecular sizes and crystal forms (anatase and rutile) in human skin keratinocytes under UVA irradiation. Our results show that all nano-TiO(2) particles caused phototoxicity, as determined by the MTS assay and by cell membrane damage measured by the lactate dehydrogenase (LDH) assay, both of which were UVA dose- and nano-TiO(2) dose-dependent. The smaller the particle size of the nano-TiO(2) the higher the cell damage. The rutile form of nano-TiO(2) showed less phototoxicity than anatase nano-TiO(2). The level of photocytotoxicity and cell membrane damage is mainly dependent on the level of reactive oxygen species (ROS) production. Using polyunsaturated lipids in plasma membranes and human serum albumin as model targets, and employing electron spin resonance (ESR) oximetry and immuno-spin trapping as unique probing methods, we demonstrated that UVA irradiation of nano-TiO(2) can induce significant cell damage, mediated by lipid and protein peroxidation. These overall results suggest that nano-TiO(2) is phototoxic to human skin keratinocytes, and that this phototoxicity is mediated by ROS generated during UVA irradiation.
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Affiliation(s)
- Jun-Jie Yin
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, United States
| | - Jun Liu
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Marilyn Ehrenshaft
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, United States
| | - Joan E. Roberts
- Fordham University, 113 West 60th Street, New York, NY 10023, United States
| | - Peter P. Fu
- National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079, United States
| | - Ronald P. Mason
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, United States
| | - Baozhong Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190, China
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Karroum O, Kengen J, Danhier P, Magat J, Mignion L, Bouzin C, Verrax J, Charette N, Starkel P, Calderon PB, Sonveaux P, Feron O, Grégoire V, Gallez B, Jordan BF. Tumor reoxygenation following administration of Mitogen-Activated Protein Kinase inhibitors: a rationale for combination with radiation therapy. Radiother Oncol 2012; 105:64-71. [PMID: 22682746 DOI: 10.1016/j.radonc.2012.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 04/12/2012] [Accepted: 05/14/2012] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND PURPOSE The relevance of Mitogen Activated Protein Kinase (MAPK) inhibitors as co-treatments for radiation therapy is investigated, with special focus on a potential link between the MAPK pathway and tumor hypoxia, which is a critical determinant for response to therapy. MATERIALS AND METHODS The effects of two MAPK inhibitors, Sorafenib and PD0325901, were monitored daily using in vivo EPR (Electron Paramagnetic Resonance) oximetry in FSaII and TLT tumor models in order to identify a window of reoxygenation, during which tumor blood flow, oxygen consumption and radiation sensitivity were assessed. RESULTS Reoxygenation was shown after two days of treatments with Sorafenib or PD0325901 in two tumor models, which was further successfully exploited with Sorafenib for improving the radiation response of FSaII tumors by a factor of 1.5. The increase in tumor oxygenation was shown to be the result of two major factors: (i) an increase in blood flow for Sorafenib, that might be linked to its anti-angiogenic effect (vascular normalization), and (ii) a decrease in oxygen consumption for Sorafenib and PD0325901, due to an alteration of the mitochondrial activity. CONCLUSION We evidenced tumor reoxygenation in vivo following MAPK inhibition and suggest a rationale for the combination of radiation therapy with Sorafenib.
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Yucel U, Elias RJ, Coupland JN. Solute distribution and stability in emulsion-based delivery systems: an EPR study. J Colloid Interface Sci 2012; 377:105-13. [PMID: 22533996 DOI: 10.1016/j.jcis.2012.03.071] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 03/22/2012] [Accepted: 03/23/2012] [Indexed: 10/28/2022]
Abstract
Oil-in-water emulsions and related systems are often used to deliver hydrophobic solutes in foods, personal care products, and pharmaceuticals. Recent work has considered the use of crystalline lipid carrier particles (i.e., solid lipid nanoparticles, SLN) to control the availability of the solute; however, there is little direct evidence for the localization of small molecules in these systems. Alkanes (10 wt.% tetradecane or eicosane) containing the spin probe 4-phenyl-2,2,5,5-tetramethyl-3-imidazoline-1-oxyl (PTMIO, 200 ppm) were homogenized into sodium caseinate solution (1 wt.%) to produce fine or coarse droplets (0.2 μm or 1.3 μm, respectively) and cooled to 21.5 °C where eicosane is crystalline and tetradecane is liquid. Analysis of the resulting EPR spectra revealed populations of probe in two discrete environments (i.e., aqueous and lipid). PTMIO is largely hydrophobic with 77% and 70% present in the coarse and fine liquid lipid droplets (i.e., tetradecane droplets), respectively. In the solid droplets (i.e., eicosane), all of the probe was excluded from the droplets into the aqueous environment. In all cases, the mobility of the probe in both lipid and aqueous environments was affected by the droplet surface; thus, we hypothesize that the majority of the probe molecules are associated with the droplet interface. The PTMIO was reduced to an EPR-silent form by the addition of iron/ascorbate to the aqueous phase, and the apparent rate constant of the reaction was proportional to the fraction of the spin probe in the aqueous phase. Based on these findings, we propose that droplet crystallization excludes solute molecules from the droplet core to the aqueous environment where they interact with the droplet surface.
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Affiliation(s)
- Umut Yucel
- Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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Bodmer SIA, Balestra GM, Harms FA, Johannes T, Raat NJH, Stolker RJ, Mik EG. Microvascular and mitochondrial PO(2) simultaneously measured by oxygen-dependent delayed luminescence. JOURNAL OF BIOPHOTONICS 2012; 5:140-151. [PMID: 22114031 DOI: 10.1002/jbio.201100082] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 11/03/2011] [Accepted: 11/03/2011] [Indexed: 05/31/2023]
Abstract
Measurement of tissue oxygenation is a complex task and various techniques have led to a wide range of tissue PO(2) values and contradictory results. Tissue is compartmentalized in microcirculation, interstitium and intracellular space and current techniques are biased towards a certain compartment. Simultaneous oxygen measurements in various compartments might be of great benefit for our understanding of determinants of tissue oxygenation. Here we report simultaneous measurement of microvascular PO(2) (μPO(2) ) and mitochondrial PO(2) (mitoPO(2) ) in rats. The μPO(2) measurements are based on oxygen-dependent quenching of phosphorescence of the near-infrared phosphor Oxyphor G2. The mitoPO(2) measurements are based on oxygen-dependent quenching of delayed fluorescence of protoporphyrin IX (PpIX). Favorable spectral properties of these porphyrins allow simultaneous measurement of the delayed luminescence lifetimes. A dedicated fiber-based time-domain setup consisting of a tunable pulsed laser, 2 red-sensitive gated photomultiplier tubes and a simultaneous sampling data-acquisition system is described in detail. The absence of cross talk between the channels is shown and the feasibility of simultaneous μPO(2) and mitoPO(2) measurements is demonstrated in rat liver in vivo. It is anticipated that this novel approach will greatly contribute to our understanding of tissue oxygenation in physiological and pathological circumstances.
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Affiliation(s)
- Sander I A Bodmer
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, Erasmus MC - University Medical Center Rotterdam, s-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands
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Hou H, Dong R, Li H, Williams B, Lariviere JP, Hekmatyar SK, Kauppinen RA, Khan N, Swartz H. Dynamic changes in oxygenation of intracranial tumor and contralateral brain during tumor growth and carbogen breathing: a multisite EPR oximetry with implantable resonators. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 214:22-8. [PMID: 22033225 PMCID: PMC3730127 DOI: 10.1016/j.jmr.2011.09.043] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/19/2011] [Accepted: 09/22/2011] [Indexed: 05/21/2023]
Abstract
INTRODUCTION Several techniques currently exist for measuring tissue oxygen; however technical difficulties have limited their usefulness and general application. We report a recently developed electron paramagnetic resonance (EPR) oximetry approach with multiple probe implantable resonators (IRs) that allow repeated measurements of oxygen in tissue at depths of greater than 10mm. METHODS The EPR signal to noise (S/N) ratio of two probe IRs was compared with that of LiPc deposits. The feasibility of intracranial tissue pO(2) measurements by EPR oximetry using IRs was tested in normal rats and rats bearing intracerebral F98 tumors. The dynamic changes in the tissue pO(2) were assessed during repeated hyperoxia with carbogen breathing. RESULTS A 6-10 times increase in the S/N ratio was observed with IRs as compared to LiPc deposits. The mean brain pO(2) of normal rats was stable and increased significantly during carbogen inhalation in experiments repeated for 3months. The pO(2) of F98 glioma declined gradually, while the pO(2) of contralateral brain essentially remained the same. Although a significant increase in the glioma pO(2) was observed during carbogen inhalation, this effect declined in experiments repeated over days. CONCLUSION EPR oximetry with IRs provides a significant increase in S/N ratio. The ability to repeatedly assess orthotopic glioma pO(2) is likely to play a vital role in understanding the dynamics of tissue pO(2) during tumor growth and therapies designed to modulate tumor hypoxia. This information could then be used to optimize chemoradiation by scheduling treatments at times of increased glioma oxygenation.
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Affiliation(s)
- Huagang Hou
- EPR Center for the Study of Viable Systems, Department of Radiology, Dartmouth Medical School, Hanover, NH 03755, United States.
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Repeated assessment of orthotopic glioma pO(2) by multi-site EPR oximetry: a technique with the potential to guide therapeutic optimization by repeated measurements of oxygen. J Neurosci Methods 2011; 204:111-117. [PMID: 22079559 DOI: 10.1016/j.jneumeth.2011.10.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 09/29/2011] [Accepted: 10/27/2011] [Indexed: 01/27/2023]
Abstract
Tumor hypoxia plays a vital role in therapeutic resistance. Consequently, measurements of tumor pO(2) could be used to optimize the outcome of oxygen-dependent therapies, such as, chemoradiation. However, the potential optimizations are restricted by the lack of methods to repeatedly and quantitatively assess tumor pO(2) during therapies, particularly in gliomas. We describe the procedures for repeated measurements of orthotopic glioma pO(2) by multi-site electron paramagnetic resonance (EPR) oximetry. This oximetry approach provides simultaneous measurements of pO(2) at more than one site in the glioma and contralateral cerebral tissue. The pO(2) of intracerebral 9L, C6, F98 and U251 tumors, as well as contralateral brain, were measured repeatedly for five consecutive days. The 9L glioma was well oxygenated with pO(2) of 27-36 mm Hg, while C6, F98 and U251 glioma were hypoxic with pO(2) of 7-12mm Hg. The potential of multi-site EPR oximetry to assess temporal changes in tissue pO(2) was investigated in rats breathing 100% O(2). A significant increase in F98 tumor and contralateral brain pO(2) was observed on day 1 and day 2, however, glioma oxygenation declined on subsequent days. In conclusion, EPR oximetry provides the capability to repeatedly assess temporal changes in orthotopic glioma pO(2). This information could be used to test and optimize the methods being developed to modulate tumor hypoxia. Furthermore, EPR oximetry could be potentially used to enhance the outcome of chemoradiation by scheduling treatments at times of increase in glioma pO(2).
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Abstract
PURPOSE OF REVIEW The holy grail of circulatory monitoring is an accurate, continuous and relatively noninvasive means of assessing the adequacy of organ perfusion. This could be then advantageously used to direct therapeutic interventions to prevent both under-treatment and over-treatment and thus improve outcomes. However, in view of the heterogeneous response (adaptive or maladaptive) of different organs to various shock states, any monitor of perfusion adequacy cannot reflect every organ system, but should at least detect early deterioration in a 'canary' organ. Tissue oxygen tension reflects the balance between local oxygen supply and demand, and could thus be a potentially useful monitoring modality. This article examines the different technologies available and reviews the current literature regarding its utility as a monitor. RECENT FINDINGS Tissue oxygen tension, measured at a variety of sites in both human and laboratory studies, does appear to be a sensitive indicator of organ perfusion in different shock states. However, responses can vary not only between organs and between different shock states, but also over time. These changes reflect the particular oxygen supply-demand balance present in that tissue bed at that specific time point in the disease process. The response to a dynamic oxygen challenge test provides further information that allows severity to be more readily differentiated. SUMMARY Monitoring of tissue oxygen tension may offer a potentially useful tool for clinical management though significant validation needs to be first performed to confirm its promise.
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Cerebral oxygenation of the cortex and striatum following normobaric hyperoxia and mild hypoxia in rats by EPR oximetry using multi-probe implantable resonators. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 701:61-7. [PMID: 21445770 DOI: 10.1007/978-1-4419-7756-4_9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Multi-site electron paramagnetic resonance (EPR) oximetry, using multi-probe implantable resonators, was used to measure the partial pressure of oxygen (pO(2)) in the brains of rats following normobaric hyperoxia and mild hypoxia. The cerebral tissue pO(2) was measured simultaneously in the cerebral cortex and striatum in the same rats before, during, and after normobaric hyperoxia and mild hypoxia challenges. The mean baseline tissue pO(2) values were not significantly different between the cortex and striatum.During 30 min of 100% O(2) inhalation, a statistically significant increase in tissue pO(2) of all four sites was observed, however, the tissue pO(2) of the striatum area was significantly higher than in the forelimb area of the cortex. Brain pO(2) significantly decreased from the baseline value during 15 min of 15% O(2) challenge.No differences in the recovery of the cerebral cortex and striatum pO(2) were observed when the rats were allowed to breathe 30% O(2). It appears that EPR oximetry using implantable resonators can provide information on pO(2) under the experimental conditions needed for such a study. The levels of pO(2) that occurred in these experiments are readily resolvable by multi-site EPR oximetry with multi-probe resonators. In addition, the ability to simultaneously measure the pO(2) in several areas of the brain provides important information that could potentially help differentiate the pO(2) changes that can occur due to global or local mechanisms.
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Lu C, Saless N, Hu D, Wang X, Xing Z, Hou H, Williams B, Swartz HM, Colnot C, Miclau T, Marcucio RS. Mechanical stability affects angiogenesis during early fracture healing. J Orthop Trauma 2011; 25:494-9. [PMID: 21738063 PMCID: PMC3167470 DOI: 10.1097/bot.0b013e31822511e0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES The goal of this study was to determine to what extent mechanical stability affects vascular repair during fracture healing. METHODS Stabilized and nonstabilized tibia fractures were created in adult mice. Fracture tissues were collected at multiple time points during early fracture healing. Vasculature in fractured limbs was visualized by immunohistochemistry with an anti-PECAM-1 antibody on tissue sections and then quantified with stereology. Oxygen tension, vascular endothelial growth factor expression, and lactate accumulation at the fracture site were measured. Gene expression was compared between stabilized and nonstabilized fractures by microarray analysis. RESULTS We found that new blood vessel formation was robust by 3 days after fracture. Quantitative analysis showed that nonstabilized fractures had higher length density and surface density than stabilized fractures at 3 days after injury, suggesting that nonstabilized fractures were more vascularized. Oximetry analysis did not detect a significant difference in oxygen tension at the fracture site between stabilized and nonstabilized fractures during the first 3 days after injury. Further microarray analysis was performed to determine the effects of mechanical stability on the expression of angiogenic factors. No significant difference in the expression of vascular endothelial growth factors and other angiogenic factors was detected between stabilized and nonstabilized fractures. CONCLUSIONS Mechanical instability promotes angiogenesis during early fracture healing and further research is required to determine the underlying mechanisms.
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Affiliation(s)
- Chuanyong Lu
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
- Columbia University Medical Center, Tissue Engineering and Regenerative Medicine Laboratory (TERML), College of Dental Medicine, New York, NY
| | - Neema Saless
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
| | - Diane Hu
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
| | - Xiaodong Wang
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
| | - Zhiqing Xing
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
| | - Huagang Hou
- EPR Center for the Study of Viable Systems, Department of Diagnostic Radiology, Dartmouth Medical School, Hanover, NH
| | - Benjamin Williams
- EPR Center for the Study of Viable Systems, Department of Diagnostic Radiology, Dartmouth Medical School, Hanover, NH
| | - Harold M. Swartz
- EPR Center for the Study of Viable Systems, Department of Diagnostic Radiology, Dartmouth Medical School, Hanover, NH
| | - Celine Colnot
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
- INSERM U781, Hopital Necker Enfants Malades, Paris, France
| | - Theodore Miclau
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
| | - Ralph S. Marcucio
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California at San Francisco, 1001 Potrero Ave., San Francisco, CA94110
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Avni R, Cohen B, Neeman M. Hypoxic stress and cancer: imaging the axis of evil in tumor metastasis. NMR IN BIOMEDICINE 2011; 24:569-81. [PMID: 21793071 PMCID: PMC3558740 DOI: 10.1002/nbm.1632] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Revised: 09/16/2010] [Accepted: 09/24/2010] [Indexed: 05/04/2023]
Abstract
Tumors emerge as a result of the sequential acquisition of genetic, epigenetic and somatic alterations promoting cell proliferation and survival. The maintenance and expansion of tumor cells rely on their ability to adapt to changes in their microenvironment, together with the acquisition of the ability to remodel their surroundings. Tumor cells interact with two types of interconnected microenvironments: the metabolic cell autonomous microenvironment and the nonautonomous cellular-molecular microenvironment comprising interactions between tumor cells and the surrounding stroma. Hypoxia is a central player in cancer progression, affecting not only tumor cell autonomous functions, such as cell division and invasion, resistance to therapy and genetic instability, but also nonautonomous processes, such as angiogenesis, lymphangiogenesis and inflammation, all contributing to metastasis. Closely related microenvironmental stressors affecting cancer progression include, in addition to hypoxia, elevated interstitial pressure and oxidative stress. Noninvasive imaging offers multiple means to monitor the tumor microenvironment and its consequences, and can thus assist in the understanding of the biological basis of hypoxia and microenvironmental stress in cancer progression, and in the development of strategies to monitor therapies targeted at stress-induced tumor progression.
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Affiliation(s)
- Reut Avni
- Department of Biological Regulation, Weizmann Institute, Rehovot, Israel
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Matute-Bello G, Downey G, Moore BB, Groshong SD, Matthay MA, Slutsky AS, Kuebler WM. An official American Thoracic Society workshop report: features and measurements of experimental acute lung injury in animals. Am J Respir Cell Mol Biol 2011; 44:725-38. [PMID: 21531958 PMCID: PMC7328339 DOI: 10.1165/rcmb.2009-0210st] [Citation(s) in RCA: 1294] [Impact Index Per Article: 99.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Acute lung injury (ALI) is well defined in humans, but there is no agreement as to the main features of acute lung injury in animal models. A Committee was organized to determine the main features that characterize ALI in animal models and to identify the most relevant methods to assess these features. We used a Delphi approach in which a series of questionnaires were distributed to a panel of experts in experimental lung injury. The Committee concluded that the main features of experimental ALI include histological evidence of tissue injury, alteration of the alveolar capillary barrier, presence of an inflammatory response, and evidence of physiological dysfunction; they recommended that, to determine if ALI has occurred, at least three of these four main features of ALI should be present. The Committee also identified key "very relevant" and "somewhat relevant" measurements for each of the main features of ALI and recommended the use of least one "very relevant" measurement and preferably one or two additional separate measurements to determine if a main feature of ALI is present. Finally, the Committee emphasized that not all of the measurements listed can or should be performed in every study, and that measurements not included in the list are by no means "irrelevant." Our list of features and measurements of ALI is intended as a guide for investigators, and ultimately investigators should choose the particular measurements that best suit the experimental questions being addressed as well as take into consideration any unique aspects of the experimental design.
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Mupparaju S, Hou H, Lariviere JP, Swartz H, Jounaidi Y, Khan N. Repeated tumor oximetry to identify therapeutic window during metronomic cyclophosphamide treatment of 9L gliomas. Oncol Rep 2011; 26:281-6. [PMID: 21503586 DOI: 10.3892/or.2011.1268] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 03/17/2011] [Indexed: 12/13/2022] Open
Abstract
Malignant gliomas are aggressive and angiogenic tumors with high VEGF content. Consequently, approaches such as metronomic chemotherapy, which have an anti-angiogenic effect, are being investigated. However, a lack of an appropriate technique that can facilitate the identification of vascular changes during antiangiogenic treatments has restricted therapeutic optimization. We have investigated the potential of tumor pO2 as a marker to detect vascular changes during metronomic chemotherapy. Electron paramagnetic resonance (EPR) oximetry was used to repeatedly assess tumor pO2 during metronomic cyclophosphamide treatment of subcutaneous 9L tumors. The 9L tumors were hypoxic with a pO2 of 5.6-8 mmHg and a tumor volume of 247-300 mm3 prior to any treatment. Tumor pO2 increased significantly to 19.7 mmHg on day 10 and remained at an elevated level until day 33 during 4 weekly treatments with 140 mg/kg cyclophosphamide. A significant decrease in the tumor volume on days 21-31 occurred in the cyclophosphamide group, while the tumor volume of the control group significantly increased during measurements for two weeks. A significant tumor growth delay was achieved with two weekly treatments of cyclophosphamide plus radiotherapy (4 Gy x 5) as compared to control, cyclophosphamide and radiotherapy alone groups. The results indicate the potential of EPR oximetry to assess tumor pO2 during metronomic chemotherapy. The ability to identify the duration of an increase in tumor pO2, therapeutic window, non-invasively by EPR oximetry could have a significant impact on the optimization of antiangiogenic approaches for the treatment of gliomas. This vital information could also be used to schedule radiotherapy to enhance therapeutic outcome.
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Affiliation(s)
- Sriram Mupparaju
- EPR Center for Viable Systems, Dartmouth Medical School, Hanover, NH 03755, USA
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