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Epel B, Viswakarma N, Hameed S, Freidin MM, Abrams CK, Kotecha M. Assessment of blood-brain barrier leakage and brain oxygenation in Connexin-32 knockout mice with systemic neuroinflammation using pulse electron paramagnetic resonance imaging techniques. Magn Reson Med 2024; 91:2519-2531. [PMID: 38193348 PMCID: PMC10997480 DOI: 10.1002/mrm.29994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/30/2023] [Accepted: 12/13/2023] [Indexed: 01/10/2024]
Abstract
PURPOSE The determination of blood-brain barrier (BBB) integrity and partial pressure of oxygen (pO2) in the brain is of substantial interest in several neurological applications. This study aimed to assess the feasibility of using trityl OX071-based pulse electron paramagnetic resonance imaging (pEPRI) to provide a quantitative estimate of BBB integrity and pO2 maps in mouse brains as a function of neuroinflammatory disease progression. METHODS Five Connexin-32 (Cx32)-knockout (KO) mice were injected with lipopolysaccharide to induce neuroinflammation for imaging. Three wild-type mice were also used to optimize the imaging procedure and as control animals. An additional seven Cx32-KO mice were used to establish the BBB leakage of trityl using the colorimetric assay. All pEPRI experiments were performed using a preclinical instrument, JIVA-25 (25 mT/720 MHz), at times t = 0, 4, and 6 h following lipopolysaccharide injection. Two pEPRI imaging techniques were used: (a) single-point imaging for obtaining spatial maps to outline the brain and calculate BBB leakage using the signal amplitude, and (b) inversion-recovery electron spin echo for obtaining pO2 maps. RESULTS A statistically significant change in BBB leakage was found using pEPRI with the progression of inflammation in Cx32 KO animals. However, the change in pO2 values with the progression of inflammation for these animals was not statistically significant. CONCLUSIONS For the first time, we show the ability of pEPRI to provide pO2 maps in mouse brains noninvasively, along with a quantitative assessment of BBB leakage. We expect this study to open new queries from the field to explore the pathology of many neurological diseases and provide a path to new treatments.
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Affiliation(s)
- Boris Epel
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois, USA
| | - Navin Viswakarma
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA
| | - Safa Hameed
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA
| | - Mona M Freidin
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Charles K Abrams
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, Illinois, USA
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA
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Kotecha M, Pagel MD. EPR Imaging and Application to Biomedical Sciences: On the 80th Anniversary of the Discovery of EPR. Mol Imaging Biol 2024:10.1007/s11307-024-01896-z. [PMID: 38243146 DOI: 10.1007/s11307-024-01896-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024]
Affiliation(s)
| | - Mark D Pagel
- University of Texas MD Anderson Cancer Center, University of Texas, Houston, TX, USA.
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Wang LH, Marfil-Garza BA, Ernst AU, Pawlick RL, Pepper AR, Okada K, Epel B, Viswakarma N, Kotecha M, Flanders JA, Datta AK, Gao HJ, You YZ, Ma M, Shapiro AMJ. Inflammation-induced subcutaneous neovascularization for the long-term survival of encapsulated islets without immunosuppression. Nat Biomed Eng 2023:10.1038/s41551-023-01145-8. [PMID: 38052996 DOI: 10.1038/s41551-023-01145-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/25/2023] [Indexed: 12/07/2023]
Abstract
Cellular therapies for type-1 diabetes can leverage cell encapsulation to dispense with immunosuppression. However, encapsulated islet cells do not survive long, particularly when implanted in poorly vascularized subcutaneous sites. Here we show that the induction of neovascularization via temporary controlled inflammation through the implantation of a nylon catheter can be used to create a subcutaneous cavity that supports the transplantation and optimal function of a geometrically matching islet-encapsulation device consisting of a twisted nylon surgical thread coated with an islet-seeded alginate hydrogel. The neovascularized cavity led to the sustained reversal of diabetes, as we show in immunocompetent syngeneic, allogeneic and xenogeneic mouse models of diabetes, owing to increased oxygenation, physiological glucose responsiveness and islet survival, as indicated by a computational model of mass transport. The cavity also allowed for the in situ replacement of impaired devices, with prompt return to normoglycemia. Controlled inflammation-induced neovascularization is a scalable approach, as we show with a minipig model, and may facilitate the clinical translation of immunosuppression-free subcutaneous islet transplantation.
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Affiliation(s)
- Long-Hai Wang
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Braulio A Marfil-Garza
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
- National Institute of Medical Sciences and Nutrition Salvador Zubiran, Mexico City, Mexico
- Tecnologico de Monterrey, School of Medicine and Health Sciences, Monterrey, Mexico
| | - Alexander U Ernst
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Rena L Pawlick
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Andrew R Pepper
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Kento Okada
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
- O2M Technologies, LLC, Chicago, IL, USA
| | | | | | | | - Ashim K Datta
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Hong-Jie Gao
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Ye-Zi You
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Minglin Ma
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
| | - A M James Shapiro
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
- Clinical Islet Transplant Program, University of Alberta, Edmonton, Alberta, Canada.
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Gertsenshteyn I, Epel B, Giurcanu M, Barth E, Lukens J, Hall K, Martinez JF, Grana M, Maggio M, Miller RC, Sundramoorthy SV, Krzykawska-Serda M, Pearson E, Aydogan B, Weichselbaum RR, Tormyshev VM, Kotecha M, Halpern HJ. Corrigendum: Absolute oxygen-guided radiation therapy improves tumor control in three preclinical tumor models. Front Med (Lausanne) 2023; 10:1339872. [PMID: 38116039 PMCID: PMC10728871 DOI: 10.3389/fmed.2023.1339872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 12/21/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fmed.2023.1269689.].
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Affiliation(s)
- Inna Gertsenshteyn
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Department of Radiology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
- O2M Technologies, Chicago, IL, United States
| | - Mihai Giurcanu
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States
| | - Eugene Barth
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - John Lukens
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Kayla Hall
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Jenipher Flores Martinez
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Mellissa Grana
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Matthew Maggio
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Richard C. Miller
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Subramanian V. Sundramoorthy
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Martyna Krzykawska-Serda
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
- Department of Biophysics and Cancer Biology, Jagiellonian University, Kraków, Poland
| | - Erik Pearson
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Bulent Aydogan
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
| | - Ralph R. Weichselbaum
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
| | | | | | - Howard J. Halpern
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging in vivo Physiology, The University of Chicago, Chicago, IL, United States
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Shaw MA, Poncelet M, Viswakarma N, Vallerini GP, Hameed S, Gluth TD, Geldenhuys WJ, Hoblitzell EH, Eubank TD, Epel B, Kotecha M, Driesschaert B. SOX71, A Biocompatible Succinyl Derivative of the Triarylmethyl Radical OX071 for In Vivo Quantitative Oxygen Mapping Using Electron Paramagnetic Resonance. Mol Imaging Biol 2023:10.1007/s11307-023-01869-8. [PMID: 37945971 DOI: 10.1007/s11307-023-01869-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/27/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023]
Abstract
PURPOSE This study aimed to develop a biocompatible oximetric electron paramagnetic resonance (EPR) spin probe with reduced self-relaxation, and sensitivity to oxygen for a higher signal-to-noise ratio and longer relaxation times at high oxygen concentration, compared to the reference spin probe OX071. PROCEDURES SOX71 was synthesized by succinylation of the twelve alcohol groups of OX071 spin probe and characterized by EPR at X-Band (9.5 GHz) and at low field (720 MHz). The biocompatibility of SOX71 was tested in vitro and in vivo in mice. A pharmacokinetic study was performed to determine the best time frame for EPR imaging. Finally, a proof-of-concept EPR oxygen imaging was performed on a mouse model of a fibrosarcoma tumor. RESULTS SOX71 was synthesized in one step from OX071. SOX71 exhibits a narrow line EPR spectrum with a peak-to-peak linewidth of 66 mG, similar to OX071. SOX71 does not bind to albumin nor show cell toxicity for the concentrations tested up to 5 mM. No toxicity was observed after systemic delivery via intraperitoneal injection in mice at twice the dose required for EPR imaging. After the injection, the probe is readily absorbed into the bloodstream, with a peak blood concentration half an hour, post-injection. Then, the probe is quickly cleared by the kidney with a half-life of ~ 45 min. SOX71 shows long relaxation times under anoxic condition (T1e = 9.5 µs and T2e = 5.1 µs; [SOX71] = 1 mM in PBS at 37 °C, pO2 = 0 mmHg, 720 MHz). Both the relaxation rates R1e and R2e show a decreased sensitivity to pO2, leading to twice longer relaxation times under room air conditions (pO2 = 159 mmHg) compared to OX071. This is ideal for oxygen imaging in samples with a wide range of pO2. Both the relaxation rates R1e and R2e show a decreased sensitivity to self-relaxation compared to OX071, with a negligible effect of the probe concentration on R1e. SOX71 was successfully applied to image oxygen in a tumor. CONCLUSION SOX71, a succinylated derivative of OX071 was synthesized, characterized, and applied for in vivo EPR tumor oxygen imaging. SOX71 is highly biocompatible, and shows decreased sensitivity to oxygen and self-relaxation. This first report suggests that SOX71 is superior to OX071 for absolute oxygen mapping under a broad range of pO2 values.
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Affiliation(s)
- Misa A Shaw
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, 26506, USA
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
- West Virginia Clinical and Translational Sciences Institute, Morgantown, WV, 26506, USA
| | - Martin Poncelet
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, 26506, USA
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
| | - Navin Viswakarma
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, IL, 60612, USA
| | | | - Safa Hameed
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, IL, 60612, USA
| | - Teresa D Gluth
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, 26506, USA
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, 26506, USA
- Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Emily H Hoblitzell
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA
| | - Timothy D Eubank
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
- West Virginia Clinical and Translational Sciences Institute, Morgantown, WV, 26506, USA
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA
- West Virginia University Cancer Institute, West Virginia University, Morgantown, WV, 26506, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA
| | - Mrignayani Kotecha
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, IL, 60612, USA.
| | - Benoit Driesschaert
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, 26506, USA.
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA.
- West Virginia Clinical and Translational Sciences Institute, Morgantown, WV, 26506, USA.
- Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA.
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA.
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Martin RM, Diaz S, Poncelet M, Driesschaert B, Barth E, Kotecha M, Epel B, Eaton GR, Biller JR. Toward a Nanoencapsulated EPR Imaging Agent for Clinical Use. Mol Imaging Biol 2023:10.1007/s11307-023-01863-0. [PMID: 37870648 PMCID: PMC11035482 DOI: 10.1007/s11307-023-01863-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/21/2023] [Accepted: 09/25/2023] [Indexed: 10/24/2023]
Abstract
PURPOSE Progress toward developing a novel radiocontrast agent for determining pO2 in tumors in a clinical setting is described. The imaging agent is designed for use with electron paramagnetic resonance imaging (EPRI), in which the collision of a paramagnetic probe molecule with molecular oxygen causes a spectroscopic change which can be calibrated to give the real oxygen concentration in the tumor tissue. PROCEDURES The imaging agent is based on a nanoscaffold of aluminum hydroxide (boehmite) with sizes from 100 to 200 nm, paramagnetic probe molecule, and encapsulation with a gas permeable, thin (10-20 nm) polymer layer to separate the imaging agent and body environment while still allowing O2 to interact with the paramagnetic probe. A specially designed deuterated Finland trityl (dFT) is covalently attached on the surface of the nanoparticle through 1,3-dipolar addition of the alkyne on the dFT with an azide on the surface of the nanoscaffold. This click-chemistry reaction affords 100% efficiency of the trityl attachment as followed by the complete disappearance of the azide peak in the infrared spectrum. The fully encapsulated, dFT-functionalized nanoparticle is referred to as RADI-Sense. RESULTS Side-by-side in vivo imaging comparisons made in a mouse model made between RADI-Sense and free paramagnetic probe (OX-071) showed oxygen sensitivity is retained and RADI-Sense can create 3D pO2 maps of solid tumors CONCLUSIONS: A novel encapsulated nanoparticle EPR imaging agent has been described which could be used in the future to bring EPR imaging for guidance of radiotherapy into clinical reality.
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Affiliation(s)
| | | | - Martin Poncelet
- Department of Pharmaceutical Sciences, School of Pharmacy & In-Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
| | - Benoit Driesschaert
- Department of Pharmaceutical Sciences, School of Pharmacy & In-Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
| | - Eugene Barth
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA
| | | | - Boris Epel
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, 60637, USA
- Oxygen Measurement Core, O2M Technologies, Chicago, IL, 60612, USA
| | - Gareth R Eaton
- Department of Chemistry, University of Denver, Denver, CO, 80210, USA
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7
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Gertsenshteyn I, Epel B, Giurcanu M, Barth E, Lukens J, Hall K, Martinez JF, Grana M, Maggio M, Miller RC, Sundramoorthy SV, Krzykawska-Serda M, Pearson E, Aydogan B, Weichselbaum RR, Tormyshev VM, Kotecha M, Halpern HJ. Absolute oxygen-guided radiation therapy improves tumor control in three preclinical tumor models. Front Med (Lausanne) 2023; 10:1269689. [PMID: 37904839 PMCID: PMC10613495 DOI: 10.3389/fmed.2023.1269689] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 09/28/2023] [Indexed: 11/01/2023] Open
Abstract
Background Clinical attempts to find benefit from specifically targeting and boosting resistant hypoxic tumor subvolumes have been promising but inconclusive. While a first preclinical murine tumor type showed significant improved control with hypoxic tumor boosts, a more thorough investigation of efficacy from boosting hypoxic subvolumes defined by electron paramagnetic resonance oxygen imaging (EPROI) is necessary. The present study confirms improved hypoxic tumor control results in three different tumor types using a clonogenic assay and explores potential confounding experimental conditions. Materials and methods Three murine tumor models were used for multi-modal imaging and radiotherapy: MCa-4 mammary adenocarcinomas, SCC7 squamous cell carcinomas, and FSa fibrosarcomas. Registered T2-weighted MRI tumor boundaries, hypoxia defined by EPROI as pO2 ≤ 10 mmHg, and X-RAD 225Cx CT boost boundaries were obtained for all animals. 13 Gy boosts were directed to hypoxic or equal-integral-volume oxygenated tumor regions and monitored for regrowth. Kaplan-Meier survival analysis was used to assess local tumor control probability (LTCP). The Cox proportional hazards model was used to assess the hazard ratio of tumor progression of Hypoxic Boost vs. Oxygenated Boost for each tumor type controlling for experimental confounding variables such as EPROI radiofrequency, tumor volume, hypoxic fraction, and delay between imaging and radiation treatment. Results An overall significant increase in LTCP from Hypoxia Boost vs. Oxygenated Boost treatments was observed in the full group of three tumor types (p < 0.0001). The effects of tumor volume and hypoxic fraction on LTCP were dependent on tumor type. The delay between imaging and boost treatments did not have a significant effect on LTCP for all tumor types. Conclusion This study confirms that EPROI locates resistant tumor hypoxic regions for radiation boost, increasing clonogenic LTCP, with potential enhanced therapeutic index in three tumor types. Preclinical absolute EPROI may provide correction for clinical hypoxia images using additional clinical physiologic MRI.
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Affiliation(s)
- Inna Gertsenshteyn
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Department of Radiology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
- O2M Technologies, Chicago, IL, United States
| | - Mihai Giurcanu
- Department of Public Health Sciences, The University of Chicago, Chicago, IL, United States
| | - Eugene Barth
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - John Lukens
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Kayla Hall
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Jenipher Flores Martinez
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Mellissa Grana
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Matthew Maggio
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Richard C. Miller
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Subramanian V. Sundramoorthy
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Martyna Krzykawska-Serda
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
- Department of Biophysics and Cancer Biology, Jagiellonian University, Kraków, Poland
| | - Erik Pearson
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
| | - Bulent Aydogan
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
| | - Ralph R. Weichselbaum
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
| | | | | | - Howard J. Halpern
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, United States
- Center for EPR Imaging In Vivo Physiology, The University of Chicago, Chicago, IL, United States
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Kotecha M, Wang L, Hameed S, Viswakarma N, Ma M, Stabler C, Hoesli CA, Epel B. In vitro oxygen imaging of acellular and cell-loaded beta cell replacement devices. Sci Rep 2023; 13:15641. [PMID: 37730815 PMCID: PMC10511476 DOI: 10.1038/s41598-023-42099-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/05/2023] [Indexed: 09/22/2023] Open
Abstract
Type 1 diabetes (T1D) is an autoimmune disease that leads to the loss of insulin-producing beta cells. Bioartificial pancreas (BAP) or beta cell replacement strategies have shown promise in curing T1D and providing long-term insulin independence. Hypoxia (low oxygen concentration) that may occur in the BAP devices due to cell oxygen consumption at the early stages after implantation damages the cells, in addition to imposing limitations to device dimensions when translating promising results from rodents to humans. Finding ways to provide cells with sufficient oxygenation remains the major challenge in realizing BAP devices' full potential. Therefore, in vitro oxygen imaging assessment of BAP devices is crucial for predicting the devices' in vivo efficiency. Electron paramagnetic resonance oxygen imaging (EPROI, also known as electron MRI or eMRI) is a unique imaging technique that delivers absolute partial pressure of oxygen (pO2) maps and has been used for cancer hypoxia research for decades. However, its applicability for assessing BAP devices has not been explored. EPROI utilizes low magnetic fields in the mT range, static gradients, and the linear relationship between the spin-lattice relaxation rate (R1) of oxygen-sensitive spin probes such as trityl OX071 and pO2 to generate oxygen maps in tissues. With the support of the Juvenile Diabetes Research Foundation (JDRF), an academic-industry partnership consortium, the "Oxygen Measurement Core" was established at O2M to perform oxygen imaging assessment of BAP devices originated from core members' laboratories. This article aims to establish the protocols and demonstrate a few examples of in vitro oxygen imaging of BAP devices using EPROI. All pO2 measurements were performed using a recently introduced 720 MHz/25 mT preclinical oxygen imager instrument, JIVA-25™. We began by performing pO2 calibration of the biomaterials used in BAPs at 25 mT magnetic field since no such data exist. We compared the EPROI pO2 measurement with a single-point probe for a few selected materials. We also performed trityl OX071 toxicity studies with fibroblasts, as well as insulin-producing cells (beta TC6, MIN6, and human islet cells). Finally, we performed proof-of-concept in vitro pO2 imaging of five BAP devices that varied in size, shape, and biomaterials. We demonstrated that EPROI is compatible with commonly used biomaterials and that trityl OX071 is nontoxic to cells. A comparison of the EPROI with a fluorescent-based point oxygen probe in selected biomaterials showed higher accuracy of EPROI. The imaging of typically heterogenous BAP devices demonstrated the utility of obtaining oxygen maps over single-point measurements. In summary, we present EPROI as a quality control tool for developing efficient cell transplantation devices and artificial tissue grafts. Although the focus of this work is encapsulation systems for diabetes, the techniques developed in this project are easily transferable to other biomaterials, tissue grafts, and cell therapy devices used in the field of tissue engineering and regenerative medicine (TERM). In summary, EPROI is a unique noninvasive tool to experimentally study oxygen distribution in cell transplantation devices and artificial tissues, which can revolutionize the treatment of degenerative diseases like T1D.
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Affiliation(s)
- Mrignayani Kotecha
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, IL, 60612, USA.
| | - Longhai Wang
- Department of Biological and Environmental Engineering, Cornell University, NY, 14853, USA
| | - Safa Hameed
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, IL, 60612, USA
| | - Navin Viswakarma
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, IL, 60612, USA
| | - Minglin Ma
- Department of Biological and Environmental Engineering, Cornell University, NY, 14853, USA
| | - Cherie Stabler
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, 32611, USA
| | - Corinne A Hoesli
- Department of Chemical Engineering, McGill University, Montreal, QC, H3C 0C5, Canada
| | - Boris Epel
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, IL, 60612, USA
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, 60637, USA
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9
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Rickard AG, Mowery YM, Bassil A, Rouse DC, Williams NT, Charity T, Belloni R, Crouch B, Ramanujam N, Stevenson D, Castillo R, Blocker S, Epel B, Kotecha M, Palmer GM. Evaluating Tumor Hypoxia Radiosensitization Via Electron Paramagnetic Resonance Oxygen Imaging (EPROI). Mol Imaging Biol 2023:10.1007/s11307-023-01855-0. [PMID: 37721686 DOI: 10.1007/s11307-023-01855-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/30/2023] [Accepted: 09/01/2023] [Indexed: 09/19/2023]
Abstract
PURPOSE Tumor hypoxia contributes to aggressive phenotypes and diminished therapeutic responses to radiation therapy (RT) with hypoxic tissue being 3-fold less radiosensitive than normoxic tissue. A major challenge in implementing hypoxic radiosensitizers is the lack of a high-resolution imaging modality that directly quantifies tissue-oxygen. The electron paramagnetic resonance oxygen-imager (EPROI) was used to quantify tumor oxygenation in two murine tumor models: E0771 syngeneic transplant breast cancers and primary p53/MCA soft tissue sarcomas, with the latter autochthonous model better recapitulating the tumor microenvironment in human malignancies. We hypothesized that tumor hypoxia differs between these models. We also aimed to quantify the absolute change in tumor hypoxia induced by the mitochondrial inhibitor papaverine (PPV) and its effect on RT response. PROCEDURES Tumor oxygenation was characterized in E0771 and primary p53/MCA sarcomas via EPROI, with the former model also being quantified indirectly via diffuse reflectance spectroscopy (DRS). After confirming PPV's effect on hypoxic fraction (via EPROI), we compared the effect of 0 versus 2 mg/kg PPV prior to 20 Gy on tumor growth delay and survival. RESULTS Hypoxic sarcomas were more radioresistant than normoxic sarcomas (p=0.0057, 2-way ANOVA), and high baseline hypoxic fraction was a significant (p=0.0063, Cox Regression Model) hazard in survivability regardless of treatment. Pre-treatment with PPV before RT did not radiosensitize tumors in the sarcoma or E0771 model. In the sarcoma model, EPROI successfully identified baseline hypoxic tumors. DRS quantification of total hemoglobin, saturated hemoglobin, changes in mitochondrial potential and glucose uptake showed no significant difference in E0771 tumors pre- and post-PPV. CONCLUSION EPROI provides 3D high-resolution pO2 quantification; EPR is better suited than DRS to characterize tumor hypoxia. PPV did not radiosensitize E0771 tumors nor p53/MCA sarcomas, which may be related to the complex pattern of vasculature in each tumor. Additionally, understanding model-dependent tumor hypoxia will provide a much-needed foundation for future therapeutic studies with hypoxic radiosensitizers.
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Affiliation(s)
- Ashlyn G Rickard
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Yvonne M Mowery
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA.
- Department of Head and Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, NC, USA.
| | - Alex Bassil
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Douglas C Rouse
- Division of Laboratory Animal Resources, Duke University School of Medicine, Durham, NC, USA
| | - Nerissa T Williams
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Theresa Charity
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Rafaela Belloni
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Brian Crouch
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Nimmi Ramanujam
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | | | - Rico Castillo
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Stephanie Blocker
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL, USA
- O2M Technologies LLC, Chicago, IL, USA
| | | | - Gregory M Palmer
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA.
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10
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Epel B, Viswakarma N, Sundramoorthy SV, Pawar NJ, Kotecha M. Oxygen Imaging of a Rabbit Tumor Using a Human-Sized Pulse Electron Paramagnetic Resonance Imager. Mol Imaging Biol 2023:10.1007/s11307-023-01852-3. [PMID: 37715089 DOI: 10.1007/s11307-023-01852-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/11/2023] [Accepted: 08/15/2023] [Indexed: 09/17/2023]
Abstract
PURPOSE Spatial heterogeneity in tumor hypoxia is one of the most important factors regulating tumor growth, development, aggressiveness, metastasis, and affecting treatment outcome. Most solid tumors are known to have hypoxia or low oxygen levels (pO2 ≤10 torr). Electron paramagnetic resonance oxygen imaging (EPROI) is an emerging oxygen mapping technology. EPROI utilizes the linear relationship between the relaxation rates of the injectable OX071 trityl spin probe and the partial oxygen pressure (pO2). However, most of the EPROI studies have been limited to mouse models of solid tumors because of the instrument-size limitations. The purpose of this work was to develop a human-sized 9-mT (250 MHz resonance frequency, 60 cm bore size) pulse EPROI instrument and evaluate its performance with rabbit VX-2 tumor oxygen imaging. METHODS A New Zealand white rabbit with a 3.2-cm VX-2 tumor in the calf muscle was imaged using the human-sized EPROI instrument and a 2.25-in. ID volume coil. The animal received a ~8-min intravenous injection of OX071 (5.2 mL total volume at 72 mM concentration) and, after 75 min, an intratumoral injection (120 μL total at 5 mM OX071 concentration) and underwent EPROI. At the end of the experiments, MRI was performed using a preclinical 9.4-T MRI system to outline the tumor boundaries. RESULTS For the first time, a human-sized pulse EPROI instrument with a 60-cm bore size/250-MHz frequency was built and evaluated using rabbit tumor oxygen imaging. For the first time, the systemic IV injection of the oxygen-sensitive trityl OX071 spin probe was used for an animal of this size. The resulting EPROI image from the IV injection showed complete tumor coverage. The image obtained after intratumoral injection showed localized coverage in the upper lobe of the tumor, demonstrating the need for improved intratumoral injection protocol. CONCLUSIONS This study demonstrates the performance of the world's first human-sized pulse EPROI instrument. It also demonstrates that the EPROI of larger animals can be performed using the systemic injection of a manageable amount of the spin probe. This brings EPROI one step closer to clinical applications in cancer therapies. Oxygen imaging is a platform technology, and the instrument and techniques developed here will also be useful for other clinical applications.
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Affiliation(s)
- Boris Epel
- O2M Technologies, LLC, Chicago, IL, 60612, USA.
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, 60637, USA.
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11
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Colombani T, Bhatt K, Epel B, Kotecha M, Bencherif SA. HIF-stabilizing biomaterials: from hypoxia-mimicking to hypoxia-inducing. Mater Adv 2023; 4:3084-3090. [PMID: 38013688 PMCID: PMC10388397 DOI: 10.1039/d3ma00090g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/05/2023] [Indexed: 08/22/2023]
Abstract
Recent advances in our understanding of hypoxia and hypoxia-mediated mechanisms shed light on the critical implications of the hypoxic stress on cellular behavior. However, tools emulating hypoxic conditions (i.e., low oxygen tensions) for research are limited and often suffer from major shortcomings, such as lack of reliability and off-target effects, and they usually fail to recapitulate the complexity of the tissue microenvironment. Fortunately, the field of biomaterials is constantly evolving and has a central role to play in the development of new technologies for conducting hypoxia-related research in several aspects of biomedical research, including tissue engineering, cancer modeling, and modern drug screening. In this perspective, we provide an overview of several strategies that have been investigated in the design and implementation of biomaterials for simulating or inducing hypoxic conditions-a prerequisite in the stabilization of hypoxia-inducible factor (HIF), a master regulator of the cellular responses to low oxygen. To this end, we discuss various advanced biomaterials, from those that integrate hypoxia-mimetic agents to artificially induce hypoxia-like responses, to those that deplete oxygen and consequently create either transient (<1 day) or sustained (>1 day) hypoxic conditions. We also aim to highlight the advantages and limitations of these emerging biomaterials for biomedical applications, with an emphasis on cancer research.
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Affiliation(s)
- Thibault Colombani
- Department of Chemical Engineering, Northeastern University Boston MA 02115 USA
| | - Khushbu Bhatt
- Department of Pharmaceutical Sciences, Northeastern University Boston MA 02115 USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago Chicago IL 60637 USA
- Oxygen Measurement Core, O2M Technologies, LLC Chicago IL 60612 USA
| | | | - Sidi A Bencherif
- Department of Chemical Engineering, Northeastern University Boston MA 02115 USA
- Department of Bioengineering, Northeastern University Boston MA 02115 USA
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University Cambridge MA 02138 USA
- Biomechanics and Bioengineering (BMBI), UTC CNRS UMR 7338, University of Technology of Compiègne, Sorbonne University 60203 Compiègne France
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12
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Viswakarma N, Siddiqui E, Patel S, Hameed S, Schreiber W, Swartz HM, Epel B, Kotecha M. In Vivo Partial Oxygen Pressure Assessment in Subcutaneous and Intraperitoneal Sites Using Imaging of Solid Oxygen Probe. Tissue Eng Part C Methods 2022; 28:264-271. [PMID: 35509263 DOI: 10.1089/ten.tec.2022.0061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The purpose of this study was to assess the natural partial oxygen pressure (pO2) of subcutaneous (SC) and intraperitoneal (IP) sites in mice to determine their relative suitability as sites for placement of implants. The pO2 measurements were performed using oxygen imaging of solid probes using lithium phthalocyanine (LiPc) as the oxygen sensitive material. LiPc is a water-insoluble crystalline probe whose spin-lattice and spin-spin relaxation rates (R1 and R2) are sensitive to the local oxygen concentration. To facilitate direct in vivo oxygen imaging, we prepared a solid probe containing encapsulated LiPc crystals in polydimethylsiloxane (PDMS), an oxygen-permeable and bioinert polymer. Although LiPc-PDMS or similar probes have been used in repeated spectroscopic or average oxygen measurements using continuous wave electron paramagnetic resonance (EPR) since the late 1990s and now have advanced to clinical applications, they have not been used for pulse EPR oxygen imaging. One LiPc-PDMS probe of 2 mm diameter and 10 mm length was implanted in SC or IP sites (left or right side) in each animal. The pO2 imaging of implanted LiPc-PDMS probes was performed weekly for 6 weeks using O2M preclinical 25 mT oxygen imager, JIVA-25™, using the pulse inversion recovery electron spin echo method. At week 6, the probes were recovered, and histological examinations were performed. We report in this study, first-ever solid probe oxygen imaging of implanted devices and pO2 assessment of SC and IP sites.
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Affiliation(s)
- Navin Viswakarma
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA
| | - Eliyas Siddiqui
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA
| | - Sonny Patel
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA
| | - Safa Hameed
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA
| | | | | | - Boris Epel
- Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA.,Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois, USA
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13
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Clayton A, Cutler A, Deligiannidis K, Lasser R, Sankoh A, Doherty J, Kotecha M. Clinical Efficacy of a 2-Week Treatment Course of Zuranolone for the Treatment of Major Depressive Disorder and Postpartum Depression: Outcomes From the Clinical Development Program. Eur Psychiatry 2022. [PMCID: PMC9567193 DOI: 10.1192/j.eurpsy.2022.282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Introduction Antidepressants that offer a rapid onset of action without requiring chronic use are greatly needed in both major depressive disorder (MDD) and postpartum depression (PPD). Zuranolone is an investigational, oral, neuroactive steroid and GABAA receptor positive allosteric modulator in clinical development as a 2-week treatment course for MDD and PPD. Objectives To present the efficacy and safety of zuranolone vs placebo in Phase 2 and 3 trials. Methods In the studies presented (Table 1), improvements in depressive symptoms were assessed by least-squares mean (LSM) using a mixed-effects model for repeated measures on the change from baseline (CFB) at Day 15 in the 17-item Hamilton Rating Scale for Depression total score (HAMD-17; primary endpoint for all trials) and the Montgomery–Åsberg Depression Rating Scale (MADRS; secondary endpoint) following a 14-day treatment course of once-daily zuranolone. ![]()
Results Compared with placebo, zuranolone treatment led to rapid improvements in depressive symptoms across clinical trials, with significant improvements (LSM treatment difference [SE] in CFB) in HAMD-17 and MADRS scores at Day 15 in 3 of the 4 trials (Table 2). Common treatment-emergent adverse events (≥5% in zuranolone treatment arms) were headache, somnolence, dizziness, nausea, sedation, diarrhea, upper respiratory tract infection, and fatigue (Table 3). No incidences of loss of consciousness or excessive sedation were observed. ![]()
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Conclusions Across the completed studies in the zuranolone clinical trial program, patients receiving zuranolone consistently experienced improvement in depressive symptoms following a 2-week treatment course. Treatment with zuranolone was generally well tolerated with a consistent safety and tolerability profile. Disclosure The MDD-201B, MOUNTAIN, and ROBIN studies were sponsored by Sage Therapeutics, Inc; the WATERFALL study was sponsored by Sage Therapeutics, Inc, and Biogen. Medical writing and editorial support were provided by MediTech Media, Ltd, and funded by Biogen.
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14
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Magana A, Giovanni R, Essien E, Epel B, Kotecha M, Liu S, Mathew MT, Hagarty SE, Bijukumar D. Amniotic growth factors enhanced human pre-adipocyte cell viability and differentiation under hypoxia. J Biomed Mater Res B Appl Biomater 2022; 110:2146-2156. [PMID: 35384274 PMCID: PMC9283253 DOI: 10.1002/jbm.b.35068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 11/10/2022]
Abstract
One of the major drawbacks associated with autologous fat grafting is unpredictable graft retention. Various efforts to improve the survivability of these cells have been explored, but these methods are time‐consuming, complex, and demand significant technical skill. In our study, we examine the use of cryopreserved amniotic membrane as a source of exogenous growth factors to improve adipocyte survivability under normal and hypoxic conditions. Human primary preadipocytes were cultured in a gelatin‐ferulic acid (Gtn‐FA) hydrogel with variable oxygen concentration and treated with amniotic membrane‐derived condition medium (CM) for 7 days. This hydrogel provides a hypoxic environment and also creates a 3D cell culture to better mimic recipient site conditions. The O2 concentration in the hydrogel was measured by electron paramagnetic resonance oxygen imaging (EPROI). The conjugation of FA was confirmed by FTIR and NMR spectroscopy. The cell viability and adipocyte differentiation were analyzed by alamarBlue™ assay, Oil Red O staining, and RT‐qPCR. The expression of genes: Pref‐1, C/EBP β, C/EBP α, PPAR‐ƴ, SLC2A4, and VEGF‐A were quantified. The cell viability results show that the 50% CM showed significantly higher cell pre‐adipocyte cell viability. In addition, compared to normal conditions, hypoxia/CM provided higher PPAR‐ƴ (p < .05), SLC2A4, and VEGF‐A (p < .05) (early and terminal differentiating markers) mRNA expression. This finding demonstrates the efficacy of amniotic CM supplementation as a novel way to promote adipocyte survival and retention via the expression of key gene markers for differentiation and angiogenesis.
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Affiliation(s)
- Alejandro Magana
- Department of Biomedical Science, University of Illinois College of Medicine at Rockford, Rockford, Illinois, USA
| | - Regina Giovanni
- Department of Biomedical Science, University of Illinois College of Medicine at Rockford, Rockford, Illinois, USA
| | - Edidiong Essien
- Department of Biomedical Science, University of Illinois College of Medicine at Rockford, Rockford, Illinois, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois, USA
| | | | - Songyun Liu
- Department of Orthopedics, Rush University of Medical Center, Chicago, Illinois, USA
| | - Mathew T Mathew
- Department of Biomedical Science, University of Illinois College of Medicine at Rockford, Rockford, Illinois, USA
| | - Sarah E Hagarty
- Department of Biomedical Science, University of Illinois College of Medicine at Rockford, Rockford, Illinois, USA.,Departments of Surgery and Biomedical Science, University of Illinois College of Medicine at Rockford, Illinois, USA
| | - Divya Bijukumar
- Department of Biomedical Science, University of Illinois College of Medicine at Rockford, Rockford, Illinois, USA
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15
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Wang LH, Ernst AU, An D, Datta AK, Epel B, Kotecha M, Ma M. A bioinspired scaffold for rapid oxygenation of cell encapsulation systems. Nat Commun 2021; 12:5846. [PMID: 34615868 PMCID: PMC8494927 DOI: 10.1038/s41467-021-26126-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 09/18/2021] [Indexed: 01/13/2023] Open
Abstract
Inadequate oxygenation is a major challenge in cell encapsulation, a therapy which holds potential to treat many diseases including type I diabetes. In such systems, cellular oxygen (O2) delivery is limited to slow passive diffusion from transplantation sites through the poorly O2-soluble encapsulating matrix, usually a hydrogel. This constrains the maximum permitted distance between the encapsulated cells and host site to within a few hundred micrometers to ensure cellular function. Inspired by the natural gas-phase tracheal O2 delivery system of insects, we present herein the design of a biomimetic scaffold featuring internal continuous air channels endowed with 10,000-fold higher O2 diffusivity than hydrogels. We incorporate the scaffold into a bulk hydrogel containing cells, which facilitates rapid O2 transport through the whole system to cells several millimeters away from the device-host boundary. A computational model, validated by in vitro analysis, predicts that cells and islets maintain high viability even in a thick (6.6 mm) device. Finally, the therapeutic potential of the device is demonstrated through the correction of diabetes in immunocompetent mice using rat islets for over 6 months.
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Affiliation(s)
- Long-Hai Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | | | - Duo An
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Ashim Kumar Datta
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL, USA
| | | | - Minglin Ma
- Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
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16
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Wang LH, Ernst AU, Flanders JA, Liu W, Wang X, Datta AK, Epel B, Kotecha M, Papas KK, Ma M. An inverse-breathing encapsulation system for cell delivery. Sci Adv 2021; 7:eabd5835. [PMID: 33990318 PMCID: PMC8121434 DOI: 10.1126/sciadv.abd5835] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 03/25/2021] [Indexed: 05/04/2023]
Abstract
Cell encapsulation represents a promising therapeutic strategy for many hormone-deficient diseases such as type 1 diabetes (T1D). However, adequate oxygenation of the encapsulated cells remains a challenge, especially in the poorly oxygenated subcutaneous site. Here, we present an encapsulation system that generates oxygen (O2) for the cells from their own waste product, carbon dioxide (CO2), in a self-regulated (i.e., "inverse breathing") way. We leveraged a gas-solid (CO2-lithium peroxide) reaction that was completely separated from the aqueous cellular environment by a gas permeable membrane. O2 measurements and imaging validated CO2-responsive O2 release, which improved cell survival in hypoxic conditions. Simulation-guided optimization yielded a device that restored normoglycemia of immunocompetent diabetic mice for over 3 months. Furthermore, functional islets were observed in scaled-up device implants in minipigs retrieved after 2 months. This inverse breathing device provides a potential system to support long-term cell function in the clinically attractive subcutaneous site.
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Affiliation(s)
- Long-Hai Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | | | | | - Wanjun Liu
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Xi Wang
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Ashim K Datta
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Boris Epel
- Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, IL 60637, USA
| | | | | | - Minglin Ma
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
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17
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Kotecha M, Epel B, Ravindran S, Dorcemus D, Nukavarapu S, Halpern H. Noninvasive Absolute Electron Paramagnetic Resonance Oxygen Imaging for the Assessment of Tissue Graft Oxygenation. Tissue Eng Part C Methods 2017; 24:14-19. [PMID: 28844179 DOI: 10.1089/ten.tec.2017.0236] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Oxygen is the single most important molecule for sustaining life and, therefore, an important variable in tissue engineering and regenerative medicine. It has been shown that the change in oxygen concentration in an artificial or tissue-engineered graft affects cell survival, differentiation, and tissue growth in profound ways. However, at present, there are no reliable methods to map partial oxygen pressure (pO2) in growing artificial tissues. Here, we adapt and test the suitability of electron paramagnetic resonance oxygen imaging (EPROI) in assessing tissue graft oxygenation in vitro. EPROI is an established method to assess absolute pO2 and has been widely applied to study tumor hypoxia in small animals. In this study, we demonstrate the feasibility of EPROI in evaluating oxygen dynamics in tissue grafts. We measured oxygen concentration in mesenchymal stem cell (MSC)-seeded polylactic-co-glycolic acid (PLGA) scaffolds with variable porosity. The pO2 maps of these scaffolds showed that the mean pO2 inside the scaffolds was smaller than the ambient air pO2 (21% oxygen, 160 torr) and was gradually increased with increasing pore size. We assessed the local oxygen dynamics of the MSC-seeded osteogenic scaffold made from collagen-chitosan hydrogels in a partially sealed Eppendorf tube. The change in pO2 values as a function of time inside the graft showed that the cells had used available oxygen within first 2 h of the experiment and then went to a dormant low oxygen consumption state until the oxygen supply was reestablished. Collectively, these data suggest that EPROI could be successfully used for mapping pO2 in tissue-engineered grafts. The knowledge of tissue graft oxygenation may be used to improve scaffold design and to assess the tissue viability and growth.
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Affiliation(s)
| | - Boris Epel
- 2 Department of Radiation and Cellular Oncology, Center for EPR Imaging In Vivo Physiology, The University of Chicago , Chicago, Illinois
| | - Sriram Ravindran
- 3 Department of Oral Biology, College of Dentistry, University of Illinois at Chicago , Chicago, Illinois
| | - Deborah Dorcemus
- 4 Orthopaedic Surgery and Department of Biomedical Engineering, University of Connecticut , Farmington, Connecticut
| | - Syam Nukavarapu
- 4 Orthopaedic Surgery and Department of Biomedical Engineering, University of Connecticut , Farmington, Connecticut
| | - Howard Halpern
- 2 Department of Radiation and Cellular Oncology, Center for EPR Imaging In Vivo Physiology, The University of Chicago , Chicago, Illinois
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18
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Epel B, Kotecha M, Halpern HJ. In vivo preclinical cancer and tissue engineering applications of absolute oxygen imaging using pulse EPR. J Magn Reson 2017; 280:149-157. [PMID: 28552587 DOI: 10.1016/j.jmr.2017.04.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 06/07/2023]
Abstract
The value of any measurement and a fortiori any measurement technology is defined by the reproducibility and the accuracy of the measurements. This implies a relative freedom of the measurement from factors confounding its accuracy. In the past, one of the reasons for the loss of focus on the importance of imaging oxygen in vivo was the difficulty in obtaining reproducible oxygen or pO2 images free from confounding variation. This review will briefly consider principles of electron paramagnetic oxygen imaging and describe how it achieves absolute oxygen measurements. We will provide a summary review of the progress in biomedical EPR imaging, predominantly in cancer biology research, discuss EPR oxygen imaging for cancer treatment and tissue graft assessment for regenerative medicine applications.
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Affiliation(s)
- Boris Epel
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, United States; Center for EPR Imaging In Vivo Physiology, University of Chicago, Chicago, IL 60637, United States
| | - Mrignayani Kotecha
- Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago IL 60607, United States
| | - Howard J Halpern
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, United States; Center for EPR Imaging In Vivo Physiology, University of Chicago, Chicago, IL 60637, United States.
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Abstract
Purpose Discomfort from light exposure leads to photophobia, glare, and poor vision in patients with congenital or trauma-induced iris damage. Commercial artificial iris lenses are static in nature to provide aesthetics without restoring the natural iris's dynamic response to light. A new photo-responsive artificial iris was therefore developed using a photochromic material with self-adaptive light transmission properties and encased in a transparent biocompatible polymer matrix. Methods The implantable artificial iris was designed and engineered using Photopia, a class of photo-responsive materials (termed naphthopyrans) embedded in polyethylene. Photopia was reshaped into annular disks that were spin-coated with polydimethylsiloxane (PDMS) to form our artificial iris lens of controlled thickness. Results Activated by UV and blue light in approximately 5 seconds with complete reversal in less than 1 minute, the artificial iris demonstrates graded attenuation of up to 40% of visible and 60% of UV light. There optical characteristics are suitable to reversibly regulate the incident light intensity. In vitro cell culture experiments showed up to 60% cell death within 10 days of exposure to Photopia, but no significant cell death observed when cultured with the artificial iris with protective encapsulation. Nuclear magnetic resonance spectroscopy confirmed these results as there was no apparent leakage of potentially toxic photochromic material from the ophthalmic device. Conclusions Our artificial iris lens mimics the functionality of the natural iris by attenuating light intensity entering the eye with its rapid reversible change in opacity and thus potentially providing an improved treatment option for patients with iris damage.
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Affiliation(s)
- Farah J Shareef
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Shan Sun
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Mrignayani Kotecha
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Iris Kassem
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States 3Medical College of Wisconsin Eye Institute, Milwaukee, Wisconsin, United States
| | - Dimitri Azar
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States 2Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Michael Cho
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States 2Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States 3Medical College of Wisconsin Eye Insti
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Majumdar S, Pothirajan P, Dorcemus D, Nukavarapu S, Kotecha M. Erratum to: High Field Sodium MRI Assessment of Stem Cell Chondrogenesis in a Tissue-Engineered Matrix. Ann Biomed Eng 2016; 44:833. [PMID: 26795975 DOI: 10.1007/s10439-016-1548-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Shreyan Majumdar
- Department of Bioengineering, University of Illinois at Chicago, 835 S. Wolcott St., W 110C, Chicago, IL, 60612, USA
| | - Padmabharathi Pothirajan
- Department of Bioengineering, University of Illinois at Chicago, 835 S. Wolcott St., W 110C, Chicago, IL, 60612, USA
| | - Deborah Dorcemus
- Orthopaedic Surgery and Department of Biomedical Engineering, University of Connecticut, Farmington, CT, 06030, USA
| | - Syam Nukavarapu
- Orthopaedic Surgery and Department of Biomedical Engineering, University of Connecticut, Farmington, CT, 06030, USA
| | - Mrignayani Kotecha
- Department of Bioengineering, University of Illinois at Chicago, 835 S. Wolcott St., W 110C, Chicago, IL, 60612, USA.
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Pothirajan P, Ravindran S, George A, Magin RL, Kotecha M. Magnetic resonance spectroscopy and imaging can differentiate between engineered bone and engineered cartilage. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:3929-32. [PMID: 25570851 DOI: 10.1109/embc.2014.6944483] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In the situation when both cartilage and its underlying bone are damaged, osteochondral tissue engineering is being developed to provide a solution. In such cases, the ability to non-invasively monitor and differentiate the development of both cartilage and bone tissues is important. Nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) have been widely used to non-invasively assess tissue-engineered cartilage and tissue-engineered bone. The purpose of this work is to assess differences in MR properties of tissue-engineered bone and tissue-engineered cartilage generated from the same cell-plus-scaffold combination at the early stage of tissue growth. We developed cartilage and bone tissue constructs by seeding human marrow stromal cells (HMSCs, 2 million/ml) in 1:1 collagen/chitosan gel for four weeks. The chondrogenic or osteogenic differentiation of cells was directed with the aid of a culture medium containing chondrogenic or osteogenic growth factors, respectively. The proton and sodium NMR and waterproton T1, T2 and diffusion MRI experiments were performed on these constructs and the control collagen/chitosan gel using a 9.4 T ((1)H freq. = 400 MHz) and a 11.7 T ((1)H freq. = 500 MHz) NMR spectrometers. In all cases, the development of bone and cartilage was found to be clearly distinguishable using NMR and MRI. We conclude that MRS and MRI are powerful tools to assess growing osteochondral tissue regeneration.
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Pothirajan P, Dorcemus D, Nukavarapu S, Kotecha M. True MRI assessment of stem cell chondrogenesis in a tissue engineered matrix. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:3933-6. [PMID: 25570852 DOI: 10.1109/embc.2014.6944484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Developing a non-invasive method to monitor the growth of tissue-engineered cartilage is of utmost importance for tracking the progress and predicting the success or failure of tissue-engineering approaches. Magnetic Resonance Imaging (MRI) is a leading non-invasive technique suitable for follow-through in preclinical and clinical stages. As complex tissue-engineering approaches are being developed for cartilage tissue engineering, it is important to develop strategies for true non-invasive MRI monitoring that can take into account contributions of the scaffold, cells and extracellular matrix (ECM) using MR parameters. In the current study, we present the preliminary MRI assessment of chondrogenic differentiation of human bone marrow derived stem cells seeded onto a specially designed osteochondral matrix system. We performed water relaxation times (T1 and T2) MRI measurements at 7, 14 and 28 days after cell seeding. The MRI experiments were performed for the tissue-engineered cartilage as well as for acellular scaffolds. We identified that the contribution of the scaffold is the dominant contribution in MR parameters of engineered cartilage and that it hinders observation of the tissue growth. An attempt is made to filter out this contribution, for the first time, in order to make a true observation of tissue growth using MRI.
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Kotecha M, Schmid TM, Odintsov B, Magin RL. Reduction of water diffusion coefficient with increased engineered cartilage matrix growth observed using MRI. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:3913-6. [PMID: 25570847 DOI: 10.1109/embc.2014.6944479] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Non-destructive monitoring of tissue-engineered cartilage growth is needed to optimize growth conditions, but extracting quantitative biomarkers of extracellular matrix development remains a technical challenge. MRI provides a non-invasive way to obtain a three dimensional map of growing tissue where the image contrast is based on tissue water relaxation times and the apparent diffusion coefficient (ADC). In this study, bovine chondrocytes were seeded in alginate beads (0, 1, 2, and 4 million cells/ml) and the ADC was measured weekly using diffusion-weighted MRI at 14.1 T over a one-month incubation period. Two groups of tissue-engineering constructs were created: one with ascorbic acid (vitamin C) added as a vitamin cofactor to increase collagen synthesis, and another with no added ascorbic acid. When normalized to the control beads without chondrocytes, the ADC was found to monotonically fall with incubation time (decreasing by up to 40% at 4 weeks), and with the administration of vitamin C. These results reflect the expected development of the extracellular matrix in the tissue-engineered constructs. We conclude that the normalized ADC is a potential biomarker for characterizing engineered cartilage tissue growth.
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Ravindran S, Kotecha M, Huang CC, Ye A, Pothirajan P, Yin Z, Magin R, George A. Biological and MRI characterization of biomimetic ECM scaffolds for cartilage tissue regeneration. Biomaterials 2015; 71:58-70. [PMID: 26318817 DOI: 10.1016/j.biomaterials.2015.08.030] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 08/15/2015] [Indexed: 01/21/2023]
Abstract
Osteoarthritis is the most common joint disorder affecting millions of people. Most scaffolds developed for cartilage regeneration fail due to vascularization and matrix mineralization. In this study we present a chondrogenic extracellular matrix (ECM) incorporated collagen/chitosan scaffold (chondrogenic ECM scaffold) for potential use in cartilage regenerative therapy. Biochemical characterization showed that these scaffolds possess key pro-chondrogenic ECM components and growth factors. MRI characterization showed that the scaffolds possess mechanical properties and diffusion characteristics important for cartilage tissue regeneration. In vivo implantation of the chondrogenic ECM scaffolds with bone marrow derived mesenchymal stem cells (MSCs) triggered chondrogenic differentiation of the MSCs without the need for external stimulus. Finally, results from in vivo MRI experiments indicate that the chondrogenic ECM scaffolds are stable and possess MR properties on par with native cartilage. Based on our results, we envision that such ECM incorporated scaffolds have great potential in cartilage regenerative therapy. Additionally, our validation of MR parameters with histology and biochemical analysis indicates the ability of MRI techniques to track the progress of our ECM scaffolds non-invasively in vivo; highlighting the translatory potential of this technology.
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Affiliation(s)
- Sriram Ravindran
- Department of Oral Biology, University of Illinois at Chicago, Chicago, IL 60612, USA.
| | - Mrignayani Kotecha
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Chun-Chieh Huang
- Department of Oral Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Allen Ye
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60612, USA
| | | | - Ziying Yin
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Richard Magin
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Anne George
- Department of Oral Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
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Zellander A, Zhao C, Kotecha M, Gemeinhart R, Wardlow M, Abiade J, Cho M. Characterization of pore structure in biologically functional poly(2-hydroxyethyl methacrylate)-poly(ethylene glycol) diacrylate (PHEMA-PEGDA). PLoS One 2014; 9:e96709. [PMID: 24816589 PMCID: PMC4016039 DOI: 10.1371/journal.pone.0096709] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/11/2014] [Indexed: 11/19/2022] Open
Abstract
A copolymer composed of poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(ethylene glycol) diacrylate (PEGDA) (PHEMA-PEGDA) is structurally versatile. Its structure can be adjusted using the following porogens: water, sucrose, and benzyl alcohol. Using phase separation technique, a variety of surface architectures and pore morphologies were developed by adjusting porogen volume and type. The water and sucrose porogens were effective in creating porous and cytocompatible PHEMA-PEGDA scaffolds. When coated with collagen, the PHEMA-PEGDA scaffolds accommodated cell migration. The PHEMA-PEGDA scaffolds are easy to produce, non-toxic, and mechanically stable enough to resist fracture during routine handling. The PHEMA-PEGDA structures presented in this study may expedite the current research effort to engineer tissue scaffolds that provide both structural stability and biological activity.
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Affiliation(s)
- Amelia Zellander
- Department of Bioengineering, University of Illinois, Chicago, Illinois, United States of America
| | - Chenlin Zhao
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, Illinois, United States of America
| | - Mrignayani Kotecha
- Department of Bioengineering, University of Illinois, Chicago, Illinois, United States of America
| | - Richard Gemeinhart
- Department of Biopharmaceutical Sciences, University of Illinois, Chicago, Illinois, United States of America
| | - Melissa Wardlow
- Department of Bioengineering, University of Illinois, Chicago, Illinois, United States of America
| | - Jeremiah Abiade
- Department of Mechanical and Industrial Engineering, University of Illinois, Chicago, Illinois, United States of America
| | - Michael Cho
- Department of Bioengineering, University of Illinois, Chicago, Illinois, United States of America
- * E-mail:
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Majumdar S, Kotecha M, Triplett W, Epel B, Halpern H. A DTI study to probe tumor microstructure and its connection with hypoxia. Annu Int Conf IEEE Eng Med Biol Soc 2014; 2014:738-41. [PMID: 25570064 PMCID: PMC4324572 DOI: 10.1109/embc.2014.6943696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Solid tumors have chaotic organization of blood vessels, disruptive nerve paths and muscle fibers that result in a hostile and heterogeneous microenvironment. These tumor regions are often hypoxic and resistant to radiation therapy. The knowledge of partial pressure of oxygen concentration (pO2), in conjunction with the information about tissue organization, can predict tissue health and may eventually be used in combination with intensity-modulated radiation therapy (IMRT) for targeted destruction of radiation-resistant areas, while sparing healthy tissues. Diffusion tensor imaging (DTI) based parameter fractional anisotropy (FA) can be used to assess organization of tissue microstructure, whereas the pO2 can be measured using electron paramagnetic resonance oxygen imaging (EPROI). This study is our first step to connect these two important physiological parameters. We calculated FA in fixed fibrosarcoma (FSa) grown in hind leg of nude mice (n = 6) using preclinical 9.4 T MRI. The FA in tumor region (0.34 ± 0.014) was found to be lower when compared to normal surrounding region (0.36 ± 0.013). We hypothesized that the change in FA is directly correlated with the change in oxygen concentration in tumor. We present preliminary in vivo results showing a positive correlation (R = 0.85, p = 0.017) between the FA and pO2 values acquired for MCa4 tumor (n = 1) using DTI and EPROI.
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Affiliation(s)
- Shreyan Majumdar
- Department of Bioengineering, University of Illinois at Chicago, Chicago IL 60612, USA
| | - Mrignayani Kotecha
- Department of Bioengineering, University of Illinois at Chicago, Chicago IL 60612, USA, phone: 312-413-2018; fax: 312-996-5921
| | - William Triplett
- Department of Physical Therapy, University of Florida, Gainesville FL 32610, USA
| | - 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
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Kotecha M, Klatt D, Magin RL. Monitoring cartilage tissue engineering using magnetic resonance spectroscopy, imaging, and elastography. Tissue Eng Part B Rev 2013; 19:470-84. [PMID: 23574498 DOI: 10.1089/ten.teb.2012.0755] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A key technical challenge in cartilage tissue engineering is the development of a noninvasive method for monitoring the composition, structure, and function of the tissue at different growth stages. Due to its noninvasive, three-dimensional imaging capabilities and the breadth of available contrast mechanisms, magnetic resonance imaging (MRI) techniques can be expected to play a leading role in assessing engineered cartilage. In this review, we describe the new MR-based tools (spectroscopy, imaging, and elastography) that can provide quantitative biomarkers for cartilage tissue development both in vitro and in vivo. Magnetic resonance spectroscopy can identify the changing molecular structure and alternations in the conformation of major macromolecules (collagen and proteoglycans) using parameters such as chemical shift, relaxation rates, and magnetic spin couplings. MRI provides high-resolution images whose contrast reflects developing tissue microstructure and porosity through changes in local relaxation times and the apparent diffusion coefficient. Magnetic resonance elastography uses low-frequency mechanical vibrations in conjunction with MRI to measure soft tissue mechanical properties (shear modulus and viscosity). When combined, these three techniques provide a noninvasive, multiscale window for characterizing cartilage tissue growth at all stages of tissue development, from the initial cell seeding of scaffolds to the development of the extracellular matrix during construct incubation, and finally, to the postimplantation assessment of tissue integration in animals and patients.
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Affiliation(s)
- Mrignayani Kotecha
- Department of Bioengineering, University of Illinois at Chicago , Chicago, Illinois
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Kotecha M, Ravindran S, Schmid TM, Vaidyanathan A, George A, Magin RL. Application of sodium triple-quantum coherence NMR spectroscopy for the study of growth dynamics in cartilage tissue engineering. NMR Biomed 2013; 26:709-17. [PMID: 23378198 PMCID: PMC3634872 DOI: 10.1002/nbm.2916] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 10/23/2012] [Accepted: 12/09/2012] [Indexed: 06/01/2023]
Abstract
We studied the tissue growth dynamics of tissue-engineered cartilage at an early growth stage after cell seeding for four weeks using sodium triple-quantum coherence NMR spectroscopy. The following tissue-engineering constructs were studied: 1) bovine chondrocytes cultured in alginate beads; 2) bovine chondrocytes cultured as pellets (scaffold-free chondrocyte pellets); and 3) human marrow stromal cells (HMSCs) seeded in collagen/chitosan based biomimetic scaffolds. We found that the sodium triple-quantum coherence spectroscopy could differentiate between different tissue-engineered constructs and native tissues based on the fast and slow components of relaxation rate as well as on the average quadrupolar coupling. Both fast (Tf ) and slow (Ts ) relaxation times were found to be longer in chondrocyte pellets and biomimetic scaffolds compared to chondrocytes suspended in alginate beads and human articular cartilage tissues. In all cases, it was found that relaxation rates and motion of sodium ions measured from correlation times were dependent on the amount of macromolecules, high cell density and anisotropy of the cartilage tissue-engineered constructs. Average quadrupolar couplings were found to be lower in the engineered tissue compared to native tissue, presumably due to the lack of order in collagen accumulated in the engineered tissue. These results support the use of sodium triple-quantum coherence spectroscopy as a tool to investigate anisotropy and growth dynamics of cartilage tissue-engineered constructs in a simple and reliable way.
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Affiliation(s)
- Mrignayani Kotecha
- Department of Bioengineering, University of Illinois at Chicago, IL 60607, USA.
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Ravindran S, Gao Q, Kotecha M, Magin RL, Karol S, Bedran-Russo A, George A. Biomimetic extracellular matrix-incorporated scaffold induces osteogenic gene expression in human marrow stromal cells. Tissue Eng Part A 2011; 18:295-309. [PMID: 21867449 DOI: 10.1089/ten.tea.2011.0136] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Engineering biomaterials mimicking the biofunctionality of the extracellular matrix (ECM) is important in instructing and eliciting cell response. The native ECM is highly dynamic and has been shown to support cellular attachment, migration, and differentiation. The advantage of synthesizing an ECM-based biomaterial is that it mimics the native cellular environment. However, the ECM has tissue-specific composition and patterned arrangement. In this study, we have employed biomimetic strategies to develop a novel collagen/chitosan template that is embedded with the native ECM of differentiating human marrow stromal cells (HMSCs) to facilitate osteoblast differentiation. The scaffold was characterized for substrate stiffness by magnetic resonance imaging and nanoindentation and by immunohistochemical analysis for the presence of key ECM proteins. Gene expression analysis showed that the ECM scaffold supported osteogenic differentiation of undifferentiated HMSCs as significant changes were observed in the expression levels of growth factors, transcription factors, proteases, receptors, and ECM proteins. Finally, we demonstrate that the scaffold had the ability to nucleate calcium phosphate polymorphs to form a mineralized matrix. The results from this study suggest that the three-dimensional native ECM scaffold directly controls cell behavior and supports the osteogenic differentiation of mesenchymal stem cells.
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Affiliation(s)
- Sriram Ravindran
- Department of Oral Biology, University of Illinois, Chicago, Illinois 60612, USA
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Brucoli F, Hawkins R, Wells G, Jenkins T, Ellis T, Kotecha M, Hochhauser D, Hartley J, Howard P, Thurston D. 526 A potent PBD-heterocyclic polyamide conjugate targeting an ICB2 transcription factor binding site. EJC Suppl 2010. [DOI: 10.1016/s1359-6349(10)72233-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Kotecha M, Wickramasinghe NP, Ishii Y. Efficient low-power heteronuclear decoupling in 13C high-resolution solid-state NMR under fast magic angle spinning. Magn Reson Chem 2007; 45 Suppl 1:S221-30. [PMID: 18157841 DOI: 10.1002/mrc.2151] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The use of a low-power two-pulse phase modulation (TPPM) sequence is proposed for efficient (1)H radio frequency (rf) decoupling in high-resolution (13)C solid-state NMR (SSNMR) under fast MAS conditions. Decoupling efficiency for different low-power decoupling sequences such as continuous-wave (cw), TPPM, XiX, and π-pulse (PIPS) train decoupling has been investigated at a spinning speed of 40 kHz for (13)C CPMAS spectra of uniformly (13)C- and (15)N-labeled L-alanine. It was found that the TPPM decoupling sequence, which was originally designed for high-power decoupling, provides the best decoupling efficiency at low power among all the low-power decoupling sequences examined here. Optimum performance of the low-power TPPM sequence was found to be obtained at a decoupling field intensity (ω(1)) of ~ω(R)/4 with a pulse flip angle of ~π and a phase alternation between ± [Symbol: see text]([Symbol: see text] = 20° ), where ω(R)/2π is the spinning speed. The sensitivity obtained for (13) CO(2)(-), (13)CH, and (13)CH(3) in L-alanine under low-power TPPM at ω(1)/2π of 10 kHz was only 5-15% less than that under high-power TPPM at ω(1) /2π of 200 kHz, despite the fact that only 0.25% of the rf power was required in low-power TPPM. Analysis of the (13)CH(2) signals for uniformly (13) C- and (15) N-labeled L-isoleucine under various low-power decoupling sequences also confirmed superior performance of the low-power TPPM sequence, although the intensity obtained by low-power TPPM was 61% of that obtained by high-power TPPM. (13)C CPMAS spectra of (13)C-labeled ubiquitin micro crystals obtained by low-power TPPM demonstrates that the low-power TPPM sequence is a practical option that provides excellent resolution and sensitivity in (13)C SSNMR for hydrated proteins.
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Affiliation(s)
- Mrignayani Kotecha
- Department of Chemistry, University of Illinois at Chicago, 845 W Taylor Street, Chicago, IL 60607, USA
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Wickramasinghe NP, Kotecha M, Samoson A, Past J, Ishii Y. Sensitivity enhancement in (13)C solid-state NMR of protein microcrystals by use of paramagnetic metal ions for optimizing (1)H T(1) relaxation. J Magn Reson 2007; 184:350-6. [PMID: 17126048 PMCID: PMC1839830 DOI: 10.1016/j.jmr.2006.10.012] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 10/21/2006] [Accepted: 10/24/2006] [Indexed: 05/04/2023]
Abstract
We discuss a simple approach to enhance sensitivity for (13)C high-resolution solid-state NMR for proteins in microcrystals by reducing (1)H T(1) relaxation times with paramagnetic relaxation reagents. It was shown that (1)H T(1) values can be reduced from 0.4-0.8s to 60-70 ms for ubiquitin and lysozyme in D(2)O in the presence of 10 mM Cu(II)Na(2)EDTA without substantial degradation of the resolution in (13)C CPMAS spectra. Faster signal accumulation using the shorter (1)H T(1) attained by paramagnetic doping provided sensitivity enhancements of 1.4-2.9 for these proteins, reducing the experimental time for a given signal-to-noise ratio by a factor of 2.0-8.4. This approach presented here is likely to be applicable to various other proteins in order to enhance sensitivity in (13)C high-resolution solid-state NMR spectroscopy.
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Affiliation(s)
- Nalinda P Wickramasinghe
- Department of Chemistry, University of Illinois at Chicago, 845 W Taylor St., Chicago, IL 60607, USA
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Kotecha M, Shukla A, Pandey L, Kumar A. Spin-diffusion approach for relaxation in bi-spaced periodic one-dimensional systems. J Magn Reson 2006; 181:113-8. [PMID: 16644251 DOI: 10.1016/j.jmr.2006.03.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Revised: 03/15/2006] [Accepted: 03/31/2006] [Indexed: 05/08/2023]
Abstract
A theoretical model for 1H-1H dipolar nuclear spin relaxation for a bi-spaced periodic one-dimensional array of spin 1/2 nuclei has been developed. A diffusion equation is formed for such a system by assuming nearest-neighbor interaction and isotropic random molecular reorientations. Under spin-diffusion conditions (omegatauc>>1), this equation has been solved using Laplace transform for an infinite chain. The results are presented for the boundary conditions described for truncated driven Nuclear Overhauser effect experiments. The solution is further generalized by making the inter-spin spacing as a random variable with a Gaussian distribution.
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Affiliation(s)
- Mrignayani Kotecha
- Department of Physics, Government of Model Science College, Jabalpur 482 001, India.
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Kotecha M, Chaudhuri S, Grey CP, Frydman L. Dynamic Effects in MAS and MQMAS NMR Spectra of Half-Integer Quadrupolar Nuclei: Calculations and an Application to the Double Perovskite Cryolite. J Am Chem Soc 2005; 127:16701-12. [PMID: 16305261 DOI: 10.1021/ja0549749] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dynamic processes such as chemical exchange or rotations between inequivalent orientations can affect the magic-angle spinning (MAS) and the multiple-quantum (MQ) MAS NMR spectra of half-integer quadrupolar nuclei. The present paper discusses such dynamic multisite MAS and MQMAS effects and applies them to study the dynamic processes that occur in the double perovskite cryolite, Na3AlF6. Dynamic line shape simulations invoking a second-order broadening of the central transition and relying on the semiclassical Bloch-McConnell formalism for chemical exchange were performed for a variety of exchange models possessing different symmetries. Fitting experimental variable-temperature cryolite 23Na NMR data with this formalism revealed that the two inequivalent sodium sites in this mineral undergo an exchange characterized by a broad distribution of rates. To further assess this dynamic process a variety of 27Al and 19F MAS NMR studies were also undertaken; quantitative 27Al-19F dipolar coupling measurements then revealed a dynamic motion of the AlF6 octahedra that were qualitatively consistent with predictions stemming from molecular dynamic simulations on this double perovskite.
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Affiliation(s)
- Mrignayani Kotecha
- Department of Chemical Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
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Abstract
We discuss the potential use of relaxation times toward the resolution of inequivalent chemical sites in the NMR spectroscopy of powdered or disordered samples. This proposal is motivated by the significant differences that can often be detected in the relaxation behavior of sites in solids, particularly when focusing on NMR observations of quadrupolar nuclei possessing different coordination and/or dynamic environments. It is shown that in these cases the implementation of a non-negative least-squares analysis on relaxation data sets enables the bidimensional resolution of overlapping powder line shapes, even when dealing with static samples. In combination with signal-enhancement methodologies such as the quadrupolar Carr-Purcell Meiboom-Gill train, such relaxation-assisted separations open up valuable routes toward the high-resolution characterization of systems involving insensitive (e.g., low-gamma) nuclei. The principles and limitations of the 2D NMR approach resulting from these considerations are discussed, and their potential is exemplified with a variety of static and spinning investigations. Their extension to other nuclear systems where spectral resolution is problematic, such as protons in organic solids, is also briefly considered.
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Affiliation(s)
- Adonis Lupulescu
- Department of Chemical Physics, Weizmann Institute of Sciences, 76100 Rehovot, Israel
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Clark B, Caparrós-Wanderley W, Musselwhite G, Kotecha M, Griffin BE. Immunity against both polyomavirus VP1 and a transgene product induced following intranasal delivery of VP1 pseudocapsid-DNA complexes. J Gen Virol 2001; 82:2791-2797. [PMID: 11602791 DOI: 10.1099/0022-1317-82-11-2791] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Murine polyomavirus VP1 virus-like particles (VLPs) can bind plasmid DNA and transport it into cells both in vitro and in vivo. Long-term expression of the transgene can be observed, suggesting that VP1 VLPs may be used as DNA delivery vehicles for gene therapy. In this study we have analysed the in vitro efficiency of transfection using different DNA/VLP molar ratios and the immune response induced following intranasal administration of these complexes to mice. Our results indicate that in short-term in vitro culture VP1 VLP-DNA complexes appear to be as efficient as DNA alone at transfecting cell monolayers. They also show that VP1 VLPs are very immunogenic, inducing high proliferative cell responses and both serum and mucosal antibodies. Moreover, VP1 VLP-DNA complexes appear to be capable of inducing a stronger immune response to the transgene product (beta-galactosidase) than immunization with DNA only. The results suggest that polyomavirus VP1 VLPs derived from the wild-type sequence may be too immunogenic for repeated use as gene delivery vehicles in gene therapy. However, due to their high immunogenicity and apparent adjuvant properties, they could be modified and used as vaccines either on their own or complexed with DNA.
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Affiliation(s)
- B Clark
- Viral Oncology Unit, Division of Medicine, ICSM at St Mary's Hospital1, BS-ICSM at St Mary's Hospital2, Norfolk Place, London W2 1PG, UK
| | - W Caparrós-Wanderley
- Viral Oncology Unit, Division of Medicine, ICSM at St Mary's Hospital1, BS-ICSM at St Mary's Hospital2, Norfolk Place, London W2 1PG, UK
| | - G Musselwhite
- Viral Oncology Unit, Division of Medicine, ICSM at St Mary's Hospital1, BS-ICSM at St Mary's Hospital2, Norfolk Place, London W2 1PG, UK
| | - M Kotecha
- Division of Life Sciences, Franklin-Wilkins Building, King's College London, 150 Stamford Street, London SE1 8WA, UK3
| | - B E Griffin
- Viral Oncology Unit, Division of Medicine, ICSM at St Mary's Hospital1, BS-ICSM at St Mary's Hospital2, Norfolk Place, London W2 1PG, UK
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Abstract
OBJECTIVE To investigate liver function tests (LFTs) changes in the puerperium and the influence of specific obstetric events on these changes. DESIGN A longitudinal observational study. SETTING West Middlesex University Hospital, Twickenham. POPULATION Ninety-four women with uncomplicated pregnancy who delivered at term. METHODS Aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyl transferase (GGT), total bilirubin (Bilirubin) and alkaline phosphatase (ALP) were measured in early labour and on day 1, day 2, day 5 and day 10 postnatal. MAIN OUTCOME MEASURES Peak enzyme concentration, time of peak enzyme concentration, the area under the curve for each enzyme and the rate of change of enzyme level from predelivery to peak concentration. RESULTS All LFTs were affected by delivery (P < 0.001), increasing by 88% (0-500%) on day 2 or day 5 for AST, 147% (0-1140%) on day 5 for ALT and 63% (0-450%) on day 5 or day 10 for GGT. Multiple linear regression showed that caesarean section and opioid administration was associated with a faster rise in AST (P = 0.001, P = 0.033 respectively). The mean peak GGT concentration was 39% higher in women having caesarean section compared with vaginal delivery (P = 0.015). Univariate analysis showed that perineal trauma, use of Entonox, maternal age at delivery and breastfeeding also influenced LFT concentration significantly. CONCLUSION Liver enzyme levels change significantly in the puerperium and are affected by common obstetric events, particularly caesarean section. This study aids clinical interpretation of postnatal LFTs in women recovering from liver-related illnesses, by facilitating the differentiation of physiological and pathological processes.
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Affiliation(s)
- A L David
- Department of Obstetrics and Gynaecology, West Middlesex University Hospital, Isleworth, UK
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Abstract
The rf pulse response of I = 3/2 spin system experiencing first order quadrupolar splitting is studied using density matrix approach. A general expression is derived in terms of spin populations, quadrupole splitting and duration and amplitude of the rf pulse for calculating the NMR signal arising due to the centre line and satellite resonances for the situation where the impressed rf pulse excites the resonances selectively as well as non-selectively. The necessary 4 X 4 transformation matrix obtained analytically by diagonalyzing the Hamiltonian are used to get the expression for the centre line response. The satellite signals are obtained in the same way but by using the numerical values of the roots of the related quartics. The widths of the corresponding pi/2-pulses are calculated for different initial spin populations. The variations of this pulse-width and the corresponding signal amplitude as a function of satellite splitting are studied.
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Affiliation(s)
- L Pandey
- Department of Physics, Rani Durgavati University, Jabalpur, India.
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Abstract
Two cases are described of blunt injury to the forearm in the absence of bone injury, resulting in an acute deep volar compartment syndrome. The importance of the deep flexor compartment of the forearm is noted. The diagnostic pitfalls and the use of intra-compartmental monitoring are discussed. We emphasize that all such cases must be admitted and carefully studied as a matter of routine. If operation is undertaken, both the superficial and deep volar compartments must be adequately decompressed.
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Kotecha M, Browne MK. Mandibular sinuses of dental origin. Practitioner 1981; 225:910-915. [PMID: 7301762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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