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Bastawrous M, Gruschke O, Soong R, Jenne A, Gross D, Busse F, Nashman B, Lacerda A, Simpson AJ. Comparing the Potential of Helmholtz and Planar NMR Microcoils for Analysis of Intact Biological Samples. Anal Chem 2022; 94:8523-8532. [DOI: 10.1021/acs.analchem.2c01560] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Monica Bastawrous
- Environmental NMR Center, Department of Physical and Environmental Science, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada
| | - Oliver Gruschke
- Bruker BioSpin GmbH, Rudolf-Plank-Str. 23, 76275 Ettlingen, Germany
| | - Ronald Soong
- Environmental NMR Center, Department of Physical and Environmental Science, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada
| | - Amy Jenne
- Environmental NMR Center, Department of Physical and Environmental Science, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada
| | - Dieter Gross
- Bruker BioSpin GmbH, Rudolf-Plank-Str. 23, 76275 Ettlingen, Germany
| | - Falko Busse
- Bruker BioSpin GmbH, Rudolf-Plank-Str. 23, 76275 Ettlingen, Germany
| | - Ben Nashman
- Synex Medical, 2 Bloor Street E, Suite 310, Toronto, Ontario M4W 1A8, Canada
| | - Andressa Lacerda
- Synex Medical, 2 Bloor Street E, Suite 310, Toronto, Ontario M4W 1A8, Canada
| | - Andre J. Simpson
- Environmental NMR Center, Department of Physical and Environmental Science, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada
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Enomoto A, Qian C, Devasahayam N, Kishimoto S, Oshima N, Blackman B, Swenson RE, Mitchell JB, Koretsky AP, Krishna MC. Wireless implantable coil with parametric amplification for in vivo electron paramagnetic resonance oximetric applications. Magn Reson Med 2018; 80:2288-2298. [PMID: 29603378 DOI: 10.1002/mrm.27185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/23/2018] [Accepted: 02/28/2018] [Indexed: 11/06/2022]
Abstract
PURPOSE To develop an implantable wireless coil with parametric amplification capabilities for time-domain electron paramagnetic resonance (EPR) spectroscopy operating at 300 MHz. METHODS The wireless coil and lithium phthalocyanine (LiPc), a solid paramagnetic probe, were each embedded individually in a biocompatible polymer polydimethoxysiloxane (PDMS). EPR signals from the LiPc embedded in PDMS (LiPc/PDMS) were generated by a transmit-receive surface coil tuned to 300 MHz. Parametric amplification was configured with an external pumping coil tuned to 600 MHz and placed between the surface coil resonator and the wireless coil. RESULTS Phantom studies showed significant enhancement in signal to noise using the pumping coil. However, no influence of the pumping coil on the oxygen-dependent EPR spectral linewidth of LiPc/PDMS was observed, suggesting the validity of parametric amplification of EPR signals for oximetry by implantation of the encapsulated wireless coil and LiPc/PDMS in deep regions of live objects. In vivo studies demonstrate the feasibility of this approach to longitudinally monitor tissue pO2 in vivo and also monitor acute changes in response to pharmacologic challenges. The encapsulated wireless coil and LiPc/PDMS engendered no host immune response when implanted for ∼3 weeks and were found to be well tolerated. CONCLUSIONS This approach may find applications for monitoring tissue oxygenation to better understand the pathophysiology associated with wound healing, organ transplantation, and ischemic diseases.
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Affiliation(s)
- Ayano Enomoto
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Chunqi Qian
- Laboratory of Functional and Molecular Imaging, NINDS, NIH, Bethesda, Maryland.,Department of Radiology, Michigan State University, East Lansing, Michigan
| | | | - Shun Kishimoto
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Nobu Oshima
- Urologic Oncology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | | | - Rolf E Swenson
- Image Probe Development Center, NHLBI, NIH, Bethesda, Maryland
| | - James B Mitchell
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
| | - Alan P Koretsky
- Laboratory of Functional and Molecular Imaging, NINDS, NIH, Bethesda, Maryland
| | - Murali C Krishna
- Radiation Biology Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland
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Ehrmann K, Saillen N, Vincent F, Stettler M, Jordan M, Wurm FM, Besse PA, Popovic R. Microfabricated solenoids and Helmholtz coils for NMR spectroscopy of mammalian cells. LAB ON A CHIP 2007; 7:373-80. [PMID: 17330169 DOI: 10.1039/b614044k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
NMR-microprobes based on solenoids and Helmholtz coils have been microfabricated and NMR-spectra of mammalian cells have successfully been taken. The microfabrication technology developed for these probes consists of three electroplated copper levels for low resistance coils and three SU-8 layers for the integration of microchannels. This technology allows fabricating solenoids, Helmholtz and planar coils on the same wafer. The coils have inner diameters in the range of 160 to 400 microm and detection volumes of 5 to 22 nL. The solenoid and Helmholtz coils show improved RF-field characteristics compared to a planar coil fabricated with the same process. The fabricated solenoid has a particularly low resistance of only 0.46 Omega at 300 MHz. Moreover, it is very sensitive and has a very uniform RF-field, but shows large line width. The Helmholtz coils are slightly less sensitive, but display a far narrower line width, and are therefore a good compromise. With a Helmholtz coil, a SNR of 620 has been measured after one scan on 9 nL pure water. An NMR-microprobe based on a Helmholtz coil has also been used to take spectra of CHO cells that have been concentrated in the sensitive region of the coil with a mechanical filter integrated into the channel.
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Affiliation(s)
- Klaus Ehrmann
- Microsystems Laboratory, EPFL-Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
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Ehrmann K, Gersbach M, Pascoal P, Vincent F, Massin C, Stamou D, Besse PA, Vogel H, Popovic RS. Sample patterning on NMR surface microcoils. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2006; 178:96-105. [PMID: 16239115 DOI: 10.1016/j.jmr.2005.08.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 08/08/2005] [Accepted: 08/31/2005] [Indexed: 05/04/2023]
Abstract
Aligned microcontact printing for patterning the sample in areas of homogeneous RF-field on the highly sensitive surface of planar NMR microprobes is presented. We experimentally demonstrate that sample patterning allows drastic improvement of the spin excitation uniformity. The NMR microprobes are designed for cell analysis and characterized using lipid vesicles as cell substitutes. Lipid vesicles are advantageous as composition and concentration of the confined solution are precisely controlled and because of their similarity to living cells. Using aligned microcontact printing, a monolayer of lipid vesicles is immobilized on the surface of the planar NMR microprobe in a patterned way. 1H NMR spectra and CPMG spin echoes of sucrose solution confined within the lipid vesicles are successfully recorded. Nutation curves of the sample structured in different patterns demonstrate the impact of patterning on the spin excitation uniformity. The total detection volumes are between 1 and 2 nL and derived with help of a theoretic model based on 3D finite element simulation. This model predicts the signal-to-noise ratio and the progression of the nutation curves.
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Affiliation(s)
- K Ehrmann
- Institute of Microsystems, EPFL-Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
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Corazza A, Vianello F, Rigo A, Cadrobbi R, Baldan N, Rigotti P, Scarpa M. Biphasic behavior of the kinetics of 31P-containing metabolites in ischemic porcine kidneys. Transplant Proc 2003; 35:3111-5. [PMID: 14697991 DOI: 10.1016/j.transproceed.2003.10.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The assessment of kidney viability before transplantation (with a view of discarding nonviable organs) remains an obstacle to confidently extending organ harvesting to marginal donors. In the present study phosphorus magnetic resonance spectroscopy was used to monitor metabolic changes in (31)P-containing metabolites in isolated porcine kidneys. After various warm ischemia times, the organs were stored at 0 degrees C. Time-dependent changes in the phosphomonoester/inorganic-phosphate ratio were recorded at 0 degrees C were shown to follow a biexponential decay. The first-order kinetic rate constant of the short-time decay was strongly dependent on the warm ischemia time, a result that was discreted in terms of the underlying biochemistry. The metabolic events responsible for the dramatic decrease in phosphomonoester/inorganic phosphate ratio that occur immediately after organ perfusion and storage, suggest that any procedure to minimize organ damage must occur immediately after harvesting.
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Affiliation(s)
- A Corazza
- Dipartimentos di Chimica Biologica, Università di Padova, Padua, Italy
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