1
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Wesseler MF, Johansen MN, Kızıltay A, Mortensen KI, Larsen NB. Optical 4D oxygen mapping of microperfused tissue models with tunable in vivo-like 3D oxygen microenvironments. LAB ON A CHIP 2022; 22:4167-4179. [PMID: 36155607 DOI: 10.1039/d2lc00063f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Sufficient and controllable oxygen supply is essential for in vitro 3D cell and tissue culture at high cell densities, which calls for volumetric in situ oxygen analysis methods to quantitatively assess the oxygen distribution. This paper presents a general approach for accurate and precise non-contact 3D mapping of oxygen tension in high cell-density cultures via embedded commercially available oxygen microsensor beads read out by confocal phosphorescence lifetime microscopy (PLIM). Optimal acquisition conditions and data analysis procedures are established and implemented in a publicly available software package. The versatility of the established method is first demonstrated in model-assisted fluidic design of microperfused 3D printed hydrogel culture chips with the aim of full culture oxygenation, and subsequently for monitoring and maintenance of physiologically relevant spatial and temporal oxygen gradients in the 3D printed chips controlled by static or dynamic flow conditions during 3D culture.
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Affiliation(s)
- Milan Finn Wesseler
- Department of Health Technology, DTU Health Tech, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Mathias Nørbæk Johansen
- Department of Health Technology, DTU Health Tech, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Aysel Kızıltay
- Department of Health Technology, DTU Health Tech, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Kim I Mortensen
- Department of Health Technology, DTU Health Tech, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | - Niels B Larsen
- Department of Health Technology, DTU Health Tech, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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2
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Schilling K, Zhai Y, Zhou Z, Zhou B, Brown E, Zhang X. High-resolution imaging of the osteogenic and angiogenic interface at the site of murine cranial bone defect repair via multiphoton microscopy. eLife 2022; 11:83146. [PMID: 36326085 PMCID: PMC9678361 DOI: 10.7554/elife.83146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/31/2022] [Indexed: 11/05/2022] Open
Abstract
The spatiotemporal blood vessel formation and specification at the osteogenic and angiogenic interface of murine cranial bone defect repair were examined utilizing a high-resolution multiphoton-based imaging platform in conjunction with advanced optical techniques that allow interrogation of the oxygen microenvironment and cellular energy metabolism in living animals. Our study demonstrates the dynamic changes of vessel types, that is, arterial, venous, and capillary vessel networks at the superior and dura periosteum of cranial bone defect, suggesting a differential coupling of the vessel type with osteoblast expansion and bone tissue deposition/remodeling during repair. Employing transgenic reporter mouse models that label distinct types of vessels at the site of repair, we further show that oxygen distributions in capillary vessels at the healing site are heterogeneous as well as time- and location-dependent. The endothelial cells coupling to osteoblasts prefer glycolysis and are less sensitive to microenvironmental oxygen changes than osteoblasts. In comparison, osteoblasts utilize relatively more OxPhos and potentially consume more oxygen at the site of repair. Taken together, our study highlights the dynamics and functional significance of blood vessel types at the site of defect repair, opening up opportunities for further delineating the oxygen and metabolic microenvironment at the interface of bone tissue regeneration.
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Affiliation(s)
- Kevin Schilling
- Center for Musculoskeletal Research, University of Rochester, School of Medicine and DentistryRochesterUnited States,Department of Biomedical Engineering, University of RochesterRochesterUnited States
| | - Yuankn Zhai
- Center for Musculoskeletal Research, University of Rochester, School of Medicine and DentistryRochesterUnited States
| | - Zhuang Zhou
- Center for Musculoskeletal Research, University of Rochester, School of Medicine and DentistryRochesterUnited States
| | - Bin Zhou
- Shanghai Institutes for Biological SciencesShanghaiChina
| | - Edward Brown
- Department of Biomedical Engineering, University of RochesterRochesterUnited States
| | - Xinping Zhang
- Center for Musculoskeletal Research, University of Rochester, School of Medicine and DentistryRochesterUnited States
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3
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Oka F, Sadeghian H, Yaseen MA, Fu B, Kura S, Qin T, Sakadžić S, Sugimoto K, Inoue T, Ishihara H, Nomura S, Suzuki M, Ayata C. Intracranial pressure spikes trigger spreading depolarizations. Brain 2021; 145:194-207. [PMID: 34245240 PMCID: PMC9126007 DOI: 10.1093/brain/awab256] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 05/29/2021] [Accepted: 06/17/2021] [Indexed: 01/09/2023] Open
Abstract
Spreading depolarizations are highly prevalent and spatiotemporally punctuated events worsening the outcome of brain injury. Trigger factors are poorly understood but may be linked to sudden worsening in supply-demand mismatch in compromised tissue. Sustained or transient elevations in intracranial pressure are also prevalent in the injured brain. Here, using a mouse model of large hemispheric ischaemic stroke, we show that mild and brief intracranial pressure elevations (20 or 30 mmHg for just 3 min) potently trigger spreading depolarizations in ischaemic penumbra (4-fold increase in spreading depolarization occurrence). We also show that 30 mmHg intracranial pressure spikes as brief as 30 s are equally effective. In contrast, sustained intracranial pressure elevations to the same level for 30 min do not significantly increase the spreading depolarization rate, suggesting that an abrupt disturbance in the steady state equilibrium is required to trigger a spreading depolarization. Laser speckle flowmetry consistently showed a reduction in tissue perfusion, and two-photon pO2 microscopy revealed a drop in venous pO2 during the intracranial pressure spikes suggesting increased oxygen extraction fraction, and therefore, worsening supply-demand mismatch. These haemodynamic changes during intracranial pressure spikes were associated with highly reproducible increases in extracellular potassium levels in penumbra. Consistent with the experimental data, a higher rate of intracranial pressure spikes was associated with spreading depolarization clusters in a retrospective series of patients with aneurysmal subarachnoid haemorrhage with strong temporal correspondence. Altogether, our data show that intracranial pressure spikes, even when mild and brief, are capable of triggering spreading depolarizations. Aggressive prevention of intracranial pressure spikes may help reduce spreading depolarization occurrence and improve outcomes after brain injury.
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Affiliation(s)
- Fumiaki Oka
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA,Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan,Correspondence to: Fumiaki Oka, MD, PhD Department of Neurosurgery, Yamaguchi Graduate School of Medicine 1-1-1, Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan E-mail:
| | - Homa Sadeghian
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Mohammad A Yaseen
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Buyin Fu
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Sreekanth Kura
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Tao Qin
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Sava Sakadžić
- Optics Division, MGH/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | - Kazutaka Sugimoto
- Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Takao Inoue
- Department of Advanced ThermoNeuroBiology, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Hideyuki Ishihara
- Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Sadahiro Nomura
- Department of Neurosurgery, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Michiyasu Suzuki
- Department of Advanced ThermoNeuroBiology, Yamaguchi Graduate School of Medicine, Ube, Yamaguchi, 755-8505, Japan
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA,Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA,Correspondence may also be addressed to: Cenk Ayata, MD, PhD Massachusetts General Hospital, 149 13th street, Room 6408, Charlestown, MA 02129, USA E-mail:
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4
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Synthesis and properties of fluorinated cyclometalated Ir(III) complexes. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.131390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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5
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Secomb TW, Bullock KV, Boas DA, Sakadžić S. The mass transfer coefficient for oxygen transport from blood to tissue in cerebral cortex. J Cereb Blood Flow Metab 2020; 40:1634-1646. [PMID: 31423930 PMCID: PMC7370375 DOI: 10.1177/0271678x19870068] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The functioning of cerebral cortex depends on adequate tissue oxygenation. MRI-based techniques allow estimation of blood oxygen levels, tissue perfusion, and oxygen consumption rate (CMRO2), but do not directly measure partial pressure of oxygen (PO2) in tissue. To address the estimation of tissue PO2, the oxygen mass transfer coefficient (KTO2) is here defined as the CMRO2 divided by the difference in spatially averaged PO2 between blood and tissue, and is estimated by analyzing Krogh-cylinder type models. Resistance to radial diffusion of oxygen from microvessels to tissue is distributed within vessels and in the extravascular tissue. The value of KTO2 is shown to depend strongly on vascular length density and also on microvessel tube hematocrits and diameters, but to be insensitive to blood flow rate and to transient changes in flow or oxygen consumption. Estimated values of KTO2 are higher than implied by previous studies, implying smaller declines in PO2 from blood to tissue. Average tissue PO2 can be estimated from MRI-based measurements as average blood PO2 minus the product of KTO2 and CMRO2. For oxygen consumption rates and vascular densities typical of mouse cortex, the predicted difference between average blood and tissue PO2 is about 10 mmHg.
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Affiliation(s)
- Timothy W Secomb
- Department of Physiology, University of Arizona, Tucson, AZ, USA.,Program in Applied Mathematics, University of Arizona, Tucson, AZ, USA.,Physiological Sciences Graduate Program, University of Arizona, Tucson, AZ, USA
| | - Katherine V Bullock
- Physiological Sciences Graduate Program, University of Arizona, Tucson, AZ, USA
| | - David A Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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6
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Li B, Esipova TV, Sencan I, Kılıç K, Fu B, Desjardins M, Moeini M, Kura S, Yaseen MA, Lesage F, Østergaard L, Devor A, Boas DA, Vinogradov SA, Sakadžić S. More homogeneous capillary flow and oxygenation in deeper cortical layers correlate with increased oxygen extraction. eLife 2019; 8:42299. [PMID: 31305237 PMCID: PMC6636997 DOI: 10.7554/elife.42299] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 07/01/2019] [Indexed: 01/01/2023] Open
Abstract
Our understanding of how capillary blood flow and oxygen distribute across cortical layers to meet the local metabolic demand is incomplete. We addressed this question by using two-photon imaging of resting-state microvascular oxygen partial pressure (PO2) and flow in the whisker barrel cortex in awake mice. Our measurements in layers I-V show that the capillary red-blood-cell flux and oxygenation heterogeneity, and the intracapillary resistance to oxygen delivery, all decrease with depth, reaching a minimum around layer IV, while the depth-dependent oxygen extraction fraction is increased in layer IV, where oxygen demand is presumably the highest. Our findings suggest that more homogeneous distribution of the physiological observables relevant to oxygen transport to tissue is an important part of the microvascular network adaptation to local brain metabolism. These results will inform the biophysical models of layer-specific cerebral oxygen delivery and consumption and improve our understanding of the diseases that affect cerebral microcirculation.
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Affiliation(s)
- Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Tatiana V Esipova
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States.,Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Ikbal Sencan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Kıvılcım Kılıç
- Department of Neurosciences, University of California, San Diego, La Jolla, United States
| | - Buyin Fu
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Michele Desjardins
- Department of Radiology, University of California, San Diego, La Jolla, United States
| | - Mohammad Moeini
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada.,Research Centre, Montreal Heart Institute, Montréal, Canada
| | - Sreekanth Kura
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Mohammad A Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Frederic Lesage
- Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, Canada.,Research Centre, Montreal Heart Institute, Montréal, Canada
| | - Leif Østergaard
- Center of Functionally Integrative Neuroscience and MINDLab, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Anna Devor
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States.,Department of Neurosciences, University of California, San Diego, La Jolla, United States.,Department of Radiology, University of California, San Diego, La Jolla, United States
| | - David A Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States.,Department of Biomedical Engineering, Boston University, Boston, United States
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States.,Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
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7
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Sullender CT, Mark AE, Clark TA, Esipova TV, Vinogradov SA, Jones TA, Dunn AK. Imaging of cortical oxygen tension and blood flow following targeted photothrombotic stroke. NEUROPHOTONICS 2018; 5:035003. [PMID: 30137881 PMCID: PMC6062776 DOI: 10.1117/1.nph.5.3.035003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 07/02/2018] [Indexed: 05/24/2023]
Abstract
We present a dual-modality imaging system combining laser speckle contrast imaging and oxygen-dependent quenching of phosphorescence to simultaneously map cortical blood flow and oxygen tension ( pO 2 ) in mice. Phosphorescence signal localization is achieved through the use of a digital micromirror device (DMD) that allows for selective excitation of arbitrary regions of interest. By targeting both excitation maxima of the oxygen-sensitive Oxyphor PtG4, we are able to examine the effects of excitation wavelength on the measured phosphorescence lifetime. We demonstrate the ability to measure the differences in pO 2 between arteries and veins and large changes during a hyperoxic challenge. We dynamically monitor blood flow and pO 2 during DMD-targeted photothrombotic occlusion of an arteriole and highlight the presence of an ischemia-induced depolarization. Chronic tracking of the ischemic lesion over eight days revealed a rapid recovery, with the targeted vessel fully reperfusing and pO 2 returning to baseline values within five days. This system has broad applications for studying the acute and chronic pathophysiology of ischemic stroke and other vascular diseases of the brain.
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Affiliation(s)
- Colin T. Sullender
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Andrew E. Mark
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Taylor A. Clark
- University of Texas at Austin, Department of Psychology, Austin, Texas, United States
- University of Texas at Austin, Institute for Neuroscience, Austin, Texas, United States
| | - Tatiana V. Esipova
- University of Pennsylvania, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
| | - Sergei A. Vinogradov
- University of Pennsylvania, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
| | - Theresa A. Jones
- University of Texas at Austin, Department of Psychology, Austin, Texas, United States
- University of Texas at Austin, Institute for Neuroscience, Austin, Texas, United States
| | - Andrew K. Dunn
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
- University of Texas at Austin, Institute for Neuroscience, Austin, Texas, United States
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8
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Kisler K, Lazic D, Sweeney MD, Plunkett S, El Khatib M, Vinogradov SA, Boas DA, Sakadži S, Zlokovic BV. In vivo imaging and analysis of cerebrovascular hemodynamic responses and tissue oxygenation in the mouse brain. Nat Protoc 2018; 13:1377-1402. [PMID: 29844521 DOI: 10.1038/nprot.2018.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebrovascular dysfunction has an important role in the pathogenesis of multiple brain disorders. Measurement of hemodynamic responses in vivo can be challenging, particularly as techniques are often not described in sufficient detail and vary between laboratories. We present a set of standardized in vivo protocols that describe high-resolution two-photon microscopy and intrinsic optical signal (IOS) imaging to evaluate capillary and arteriolar responses to a stimulus, regional hemodynamic responses, and oxygen delivery to the brain. The protocol also describes how to measure intrinsic NADH fluorescence to understand how blood O2 supply meets the metabolic demands of activated brain tissue, and to perform resting-state absolute oxygen partial pressure (pO2) measurements of brain tissue. These methods can detect cerebrovascular changes at far higher resolution than MRI techniques, although the optical nature of these techniques limits their achievable imaging depths. Each individual procedure requires 1-2 h to complete, with two to three procedures typically performed per animal at a time. These protocols are broadly applicable in studies of cerebrovascular function in healthy and diseased brain in any of the existing mouse models of neurological and vascular disorders. All these procedures can be accomplished by a competent graduate student or experienced technician, except the two-photon measurement of absolute pO2 level, which is better suited to a more experienced, postdoctoral-level researcher.
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Affiliation(s)
- Kassandra Kisler
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Divna Lazic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA.,Department of Neurobiology, Institute for Biological Research, University of Belgrade, Belgrade, Republic of Serbia
| | - Melanie D Sweeney
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Shane Plunkett
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mirna El Khatib
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - David A Boas
- Optics Division, MGH/HMS/MIT Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA.,Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Sava Sakadži
- Optics Division, MGH/HMS/MIT Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Berislav V Zlokovic
- Department of Physiology and Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
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9
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Uhlirova H, Kılıç K, Tian P, Sakadžić S, Gagnon L, Thunemann M, Desjardins M, Saisan PA, Nizar K, Yaseen MA, Hagler DJ, Vandenberghe M, Djurovic S, Andreassen OA, Silva GA, Masliah E, Kleinfeld D, Vinogradov S, Buxton RB, Einevoll GT, Boas DA, Dale AM, Devor A. The roadmap for estimation of cell-type-specific neuronal activity from non-invasive measurements. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0356. [PMID: 27574309 DOI: 10.1098/rstb.2015.0356] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2016] [Indexed: 12/22/2022] Open
Abstract
The computational properties of the human brain arise from an intricate interplay between billions of neurons connected in complex networks. However, our ability to study these networks in healthy human brain is limited by the necessity to use non-invasive technologies. This is in contrast to animal models where a rich, detailed view of cellular-level brain function with cell-type-specific molecular identity has become available due to recent advances in microscopic optical imaging and genetics. Thus, a central challenge facing neuroscience today is leveraging these mechanistic insights from animal studies to accurately draw physiological inferences from non-invasive signals in humans. On the essential path towards this goal is the development of a detailed 'bottom-up' forward model bridging neuronal activity at the level of cell-type-specific populations to non-invasive imaging signals. The general idea is that specific neuronal cell types have identifiable signatures in the way they drive changes in cerebral blood flow, cerebral metabolic rate of O2 (measurable with quantitative functional Magnetic Resonance Imaging), and electrical currents/potentials (measurable with magneto/electroencephalography). This forward model would then provide the 'ground truth' for the development of new tools for tackling the inverse problem-estimation of neuronal activity from multimodal non-invasive imaging data.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.
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Affiliation(s)
- Hana Uhlirova
- Department of Radiology, UCSD, La Jolla, CA 92093, USA CEITEC-Central European Institute of Technology and Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic
| | - Kıvılcım Kılıç
- Department of Neurosciences, UCSD, La Jolla, CA 92093, USA
| | - Peifang Tian
- Department of Neurosciences, UCSD, La Jolla, CA 92093, USA Department of Physics, John Carroll University, University Heights, OH 44118, USA
| | - Sava Sakadžić
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | - Louis Gagnon
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | | | | | - Payam A Saisan
- Department of Neurosciences, UCSD, La Jolla, CA 92093, USA
| | - Krystal Nizar
- Neurosciences Graduate Program, UCSD, La Jolla, CA 92093, USA
| | - Mohammad A Yaseen
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | | | - Matthieu Vandenberghe
- Department of Radiology, UCSD, La Jolla, CA 92093, USA NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and University of Oslo, 0407 Oslo, Norway
| | - Srdjan Djurovic
- Department of Medical Genetics, Oslo University Hospital, 0407 Oslo, Norway NORMENT, KG Jebsen Centre for Psychosis Research, Department of Clinical Science, University of Bergen, 5020 Bergen, Norway
| | - Ole A Andreassen
- NORMENT, KG Jebsen Centre for Psychosis Research, Division of Mental Health and Addiction, Oslo University Hospital and University of Oslo, 0407 Oslo, Norway
| | - Gabriel A Silva
- Department of Bioengineering, UCSD, La Jolla, CA 92093, USA Department of Opthalmology, UCSD, La Jolla, CA 92093, USA
| | | | - David Kleinfeld
- Department of Physics, UCSD, La Jolla, CA 92093, USA Department of Electrical and Computer Engineering, UCSD, La Jolla, CA 92093, USA Section of Neurobiology, UCSD, La Jolla, CA 92093, USA
| | - Sergei Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Gaute T Einevoll
- Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, 1432 Ås, Norway Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - David A Boas
- Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
| | - Anders M Dale
- Department of Radiology, UCSD, La Jolla, CA 92093, USA Department of Neurosciences, UCSD, La Jolla, CA 92093, USA
| | - Anna Devor
- Department of Radiology, UCSD, La Jolla, CA 92093, USA Department of Neurosciences, UCSD, La Jolla, CA 92093, USA Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Charlestown, MA 02129, USA
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10
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Abstract
Molecular oxygen (O2) is essential to brain function and mechanisms necessary to regulate variations in delivery or utilization of O2 are crucial to support normal brain homeostasis, physiology and energy metabolism. Any imbalance in cerebral tissue partial pressure of O2 (pO2) levels may lead to pathophysiological complications including increased reactive O2 species generation leading to oxidative stress when tissue O2 level is too high or too low. Accordingly, the need for oximetry methods, which assess cerebral pO2in vivo and in real time, is imperative to understand the role of O2 in various metabolic and disease states, including the effects of treatment and therapy options. In this review, we provide a brief overview of the common in vivo oximetry methodologies for measuring cerebral pO2. We discuss the advantages and limitations of oximetry methodologies to measure cerebral pO2in vivo followed by a more in-depth review of electron paramagnetic resonance oximetry spectroscopy and imaging using several examples of current electron paramagnetic resonance oximetry applications in the brain.
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Affiliation(s)
- John M Weaver
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.,Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Ke Jian Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.,Center of Biomedical Research Excellence, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.,Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
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11
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Gagnon L, Smith AF, Boas DA, Devor A, Secomb TW, Sakadžić S. Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation. Front Comput Neurosci 2016; 10:82. [PMID: 27630556 PMCID: PMC5006088 DOI: 10.3389/fncom.2016.00082] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/25/2016] [Indexed: 01/09/2023] Open
Abstract
Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1) interpretation of functional Magnetic Resonance Imaging (fMRI) signals, and (2) investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These “bottom-up” models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.
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Affiliation(s)
- Louis Gagnon
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School Charlestown, MA, USA
| | - Amy F Smith
- Institut de Mécanique des Fluides de ToulouseToulouse, France; Department of Physiology, University of ArizonaTucson, AZ, USA
| | - David A Boas
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School Charlestown, MA, USA
| | - Anna Devor
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical SchoolCharlestown, MA, USA; Departments of Neurosciences and Radiology, University of California, San DiegoLa Jolla, CA, USA
| | | | - Sava Sakadžić
- Optics Division, Department of Radiology, MHG/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School Charlestown, MA, USA
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12
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Yaseen MA, Srinivasan VJ, Gorczynska I, Fujimoto JG, Boas DA, Sakadžić S. Multimodal optical imaging system for in vivo investigation of cerebral oxygen delivery and energy metabolism. BIOMEDICAL OPTICS EXPRESS 2015; 6:4994-5007. [PMID: 26713212 PMCID: PMC4679272 DOI: 10.1364/boe.6.004994] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/09/2015] [Accepted: 11/14/2015] [Indexed: 05/09/2023]
Abstract
Improving our understanding of brain function requires novel tools to observe multiple physiological parameters with high resolution in vivo. We have developed a multimodal imaging system for investigating multiple facets of cerebral blood flow and metabolism in small animals. The system was custom designed and features multiple optical imaging capabilities, including 2-photon and confocal lifetime microscopy, optical coherence tomography, laser speckle imaging, and optical intrinsic signal imaging. Here, we provide details of the system's design and present in vivo observations of multiple metrics of cerebral oxygen delivery and energy metabolism, including oxygen partial pressure, microvascular blood flow, and NADH autofluorescence.
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Affiliation(s)
- Mohammad A. Yaseen
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
| | - Vivek J. Srinivasan
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
- Current Affiliation: Department of Biomedical Engineering, University of California, Davis, Davis, California,
USA
| | - Iwona Gorczynska
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts,
USA
- Current Affiliation: Department of Biophysics and Medical Physics, Institute of Physics, Nicolaus Copernicus University, Torun,
Poland
| | - James G. Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts,
USA
| | - David A. Boas
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
| | - Sava Sakadžić
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts,
USA
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13
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Maeda A, Kulbatski I, DaCosta RS. Emerging Applications for Optically Enabled Intravital Microscopic Imaging in Radiobiology. Mol Imaging 2015. [DOI: 10.2310/7290.2015.00022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Azusa Maeda
- From the Princess Margaret Cancer Centre, University Health Network, MaRS Centre; Techna Institute for Advancement of Technologies for Health; and Department of Medical Biophysics, University of Toronto, MaRS Centre, Toronto, ON
| | - Iris Kulbatski
- From the Princess Margaret Cancer Centre, University Health Network, MaRS Centre; Techna Institute for Advancement of Technologies for Health; and Department of Medical Biophysics, University of Toronto, MaRS Centre, Toronto, ON
| | - Ralph S. DaCosta
- From the Princess Margaret Cancer Centre, University Health Network, MaRS Centre; Techna Institute for Advancement of Technologies for Health; and Department of Medical Biophysics, University of Toronto, MaRS Centre, Toronto, ON
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14
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Lehner P, Staudinger C, Borisov SM, Regensburger J, Klimant I. Intrinsic Artefacts in Optical Oxygen Sensors-How Reliable are our Measurements? Chemistry 2015; 21:3978-86. [DOI: 10.1002/chem.201406037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Indexed: 11/07/2022]
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15
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Khan AA, Fullerton-Shirey SK, Howard SS. Easily prepared ruthenium-complex nanomicelle probes for two-photon quantitative imaging of oxygen in aqueous media. RSC Adv 2015. [DOI: 10.1039/c4ra11229f] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Easily prepared, biocompatible, and oxygen-sensitive optical probes with a large two-photon cross-section: towards inexpensive quantitative oxygen imaging in vivo.
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Affiliation(s)
- Aamir A. Khan
- Department of Electrical Engineering
- University of Notre Dame
- Notre Dame
- USA
| | | | - Scott S. Howard
- Department of Electrical Engineering
- University of Notre Dame
- Notre Dame
- USA
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16
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Roussakis E, Spencer JA, Lin CP, Vinogradov SA. Two-photon antenna-core oxygen probe with enhanced performance. Anal Chem 2014; 86:5937-45. [PMID: 24848643 PMCID: PMC4066907 DOI: 10.1021/ac501028m] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recent development of two-photon phosphorescence lifetime microscopy (2PLM) of oxygen enabled first noninvasive high-resolution measurements of tissue oxygenation in vivo in 3D, providing valuable physiological information. The so far developed two-photon-enhanced phosphorescent probes comprise antenna-core constructs, in which two-photon absorbing chromophores (antenna) capture and channel excitation energy to a phosphorescent core (metalloporphyrin) via intramolecular excitation energy transfer (EET). These probes allowed demonstration of the methods' potential; however, they suffer from a number of limitations, such as partial loss of emissivity to competing triplet state deactivation pathways (e.g., electron transfer) and suboptimal sensitivity to oxygen, thereby limiting spatial and temporal resolution of the method. Here we present a new probe, PtTCHP-C307, designed to overcome these limitations. The key improvements include significant increase in the phosphorescence quantum yield, higher efficiency of the antenna-core energy transfer, minimized quenching of the phosphorescence by electron transfer and increased signal dynamic range. For the same excitation flux, the new probe is able to produce up to 6-fold higher signal output than previously reported molecules. Performance of PtTCHP-C307 was demonstrated in vivo in pO2 measurements through the intact mouse skull into the bone marrow, where all blood cells are made from hematopoietic stem cells.
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Affiliation(s)
- Emmanuel Roussakis
- Department of Biochemistry and Biophysics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
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17
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Wang XD, Wolfbeis OS. Optical methods for sensing and imaging oxygen: materials, spectroscopies and applications. Chem Soc Rev 2014; 43:3666-761. [PMID: 24638858 DOI: 10.1039/c4cs00039k] [Citation(s) in RCA: 550] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We review the current state of optical methods for sensing oxygen. These have become powerful alternatives to electrochemical detection and in the process of replacing the Clark electrode in many fields. The article (with 694 references) is divided into main sections on direct spectroscopic sensing of oxygen, on absorptiometric and luminescent probes, on polymeric matrices and supports, on additives and related materials, on spectroscopic schemes for read-out and imaging, and on sensing formats (such as waveguide sensing, sensor arrays, multiple sensors and nanosensors). We finally discuss future trends and applications and summarize the properties of the most often used indicator probes and polymers. The ESI† (with 385 references) gives a selection of specific applications of such sensors in medicine, biology, marine and geosciences, intracellular sensing, aerodynamics, industry and biotechnology, among others.
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Affiliation(s)
- Xu-dong Wang
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany.
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18
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Functional Imaging of Cerebral Oxygenation with Intrinsic Optical Contrast and Phosphorescent Probes. NEUROMETHODS 2014. [DOI: 10.1007/978-1-62703-785-3_14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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19
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Kazmi SMS, Salvaggio AJ, Estrada AD, Hemati MA, Shaydyuk NK, Roussakis E, Jones TA, Vinogradov SA, Dunn AK. Three-dimensional mapping of oxygen tension in cortical arterioles before and after occlusion. BIOMEDICAL OPTICS EXPRESS 2013; 4:1061-73. [PMID: 23847732 PMCID: PMC3704088 DOI: 10.1364/boe.4.001061] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 06/07/2013] [Accepted: 06/07/2013] [Indexed: 05/21/2023]
Abstract
Occlusions in single cortical microvessels lead to a reduction in oxygen supply, but this decrement has not been able to be quantified in three dimensions at the level of individual vessels using a single instrument. We demonstrate a combined optical system using two-photon phosphorescence lifetime and fluorescence microscopy (2PLM) to characterize the partial pressure of oxygen (pO2) in single descending cortical arterioles in the mouse brain before and after generating a targeted photothrombotic occlusion. Integrated real-time Laser Speckle Contrast Imaging (LSCI) provides wide-field perfusion maps that are used to monitor and guide the occlusion process while 2PLM maps changes in intravascular oxygen tension. We present the technique's utility in highlighting the effects of vascular networking on the residual intravascular oxygen tensions measured after occlusion in three dimensions.
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Affiliation(s)
- S. M. Shams Kazmi
- Department of Biomedical Engineering, The University of Texas at
Austin, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Anthony J. Salvaggio
- Department of Biomedical Engineering, The University of Texas at
Austin, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Arnold D. Estrada
- Department of Biomedical Engineering, The University of Texas at
Austin, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Michael A. Hemati
- Department of Biomedical Engineering, The University of Texas at
Austin, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Nazariy K. Shaydyuk
- Department of Biomedical Engineering, The University of Texas at
Austin, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
| | - Emannuel Roussakis
- Department of Biochemistry and Biophysics, Perelman School of
Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, Pennsylvania 19104,
USA
| | - Theresa A. Jones
- Department of Psychology, The University of Texas at Austin, 108 E.
Dean Keeton A8000, Austin, Texas 78712, USA
| | - Sergei A. Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of
Medicine, University of Pennsylvania, 3700 Hamilton Walk, Philadelphia, Pennsylvania 19104,
USA
| | - Andrew K. Dunn
- Department of Biomedical Engineering, The University of Texas at
Austin, 107 W. Dean Keeton C0800, Austin, Texas 78712, USA
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20
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Borisov SM, Saf R, Fischer R, Klimant I. Synthesis and Properties of New Phosphorescent Red Light-Excitable Platinum(II) and Palladium(II) Complexes with Schiff Bases for Oxygen Sensing and Triplet–Triplet Annihilation-Based Upconversion. Inorg Chem 2012; 52:1206-16. [DOI: 10.1021/ic301440k] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Sergey M. Borisov
- Institute of Analytical
Chemistry and Food Chemistry, ‡Institute of Chemistry and Technology of Materials, and §Institute of Inorganic
Chemistry, Graz University of Technology, Stremayrgasse 9, 8010, Graz, Austria
| | - Robert Saf
- Institute of Analytical
Chemistry and Food Chemistry, ‡Institute of Chemistry and Technology of Materials, and §Institute of Inorganic
Chemistry, Graz University of Technology, Stremayrgasse 9, 8010, Graz, Austria
| | - Roland Fischer
- Institute of Analytical
Chemistry and Food Chemistry, ‡Institute of Chemistry and Technology of Materials, and §Institute of Inorganic
Chemistry, Graz University of Technology, Stremayrgasse 9, 8010, Graz, Austria
| | - Ingo Klimant
- Institute of Analytical
Chemistry and Food Chemistry, ‡Institute of Chemistry and Technology of Materials, and §Institute of Inorganic
Chemistry, Graz University of Technology, Stremayrgasse 9, 8010, Graz, Austria
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21
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Boros E, Polasek M, Zhang Z, Caravan P. Gd(DOTAla): a single amino acid Gd-complex as a modular tool for high relaxivity MR contrast agent development. J Am Chem Soc 2012; 134:19858-68. [PMID: 23157602 DOI: 10.1021/ja309187m] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
MR imaging at high magnetic fields benefits from an increased signal-to-noise ratio; however T(1)-based MR contrast agents show decreasing relaxivity (r(1)) at higher fields. High field, high relaxivity contrast agents can be designed by carefully controlling the rotational dynamics of the molecule. To this end, we investigated applications of the alanine analogue of Gd(DOTA), Gd(DOTAla). Fmoc-protected DOTAla suitable for solid phase peptide synthesis was synthesized and integrated into polypeptide structures. Gd(III) coordination results in very rigid attachment of the metal chelate to the peptide backbone through both the amino acid side chain and coordination of the amide carbonyl. Linear and cyclic monomers (GdL1, GdC1), dimers (Gd(2)L2, Gd(2)C2), and trimers (Gd(3)L3, Gd(3)C3) were prepared and relaxivities were determined at different field strengths ranging from 0.47 to 11.7 T. Amide carbonyl coordination was indirectly confirmed by determination of the hydration number q for the EuL1 integrated into a peptide backbone, q = 0.96 ± 0.09. The water residency time of GdL1 at 37 °C was optimal for relaxivity, τ(M) = 17 ± 2 ns. Increased molecular size leads to increased per Gd relaxivity (from r(1) = 7.5 for GdL1 to 12.9 mM(-1) s(-1) for Gd(3)L3 at 1.4 T, 37 °C). The cyclic, multimeric derivatives exhibited slightly higher relaxivities than the corresponding linearized multimers (Gd(2)C2: r(1) = 10.5 mM(-1) s(-1) versus Gd(2)C2-red r(1) = 9 mM(-1) s(-1) at 1.4 T, 37 °C). Overall, all six synthesized Gd complexes had higher relaxivities at low, intermediate, and high fields than the clinically used small molecule contrast agent [Gd(HP-DO3A)(H(2)O)].
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Affiliation(s)
- Eszter Boros
- The Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, Massachusetts 02129, United States
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22
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Devor A, Sakadžić S, Srinivasan VJ, Yaseen MA, Nizar K, Saisan PA, Tian P, Dale AM, Vinogradov SA, Franceschini MA, Boas DA. Frontiers in optical imaging of cerebral blood flow and metabolism. J Cereb Blood Flow Metab 2012; 32:1259-76. [PMID: 22252238 PMCID: PMC3390808 DOI: 10.1038/jcbfm.2011.195] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In vivo optical imaging of cerebral blood flow (CBF) and metabolism did not exist 50 years ago. While point optical fluorescence and absorption measurements of cellular metabolism and hemoglobin concentrations had already been introduced by then, point blood flow measurements appeared only 40 years ago. The advent of digital cameras has significantly advanced two-dimensional optical imaging of neuronal, metabolic, vascular, and hemodynamic signals. More recently, advanced laser sources have enabled a variety of novel three-dimensional high-spatial-resolution imaging approaches. Combined, as we discuss here, these methods are permitting a multifaceted investigation of the local regulation of CBF and metabolism with unprecedented spatial and temporal resolution. Through multimodal combination of these optical techniques with genetic methods of encoding optical reporter and actuator proteins, the future is bright for solving the mysteries of neurometabolic and neurovascular coupling and translating them to clinical utility.
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Affiliation(s)
- Anna Devor
- Department of Neurosciences, UCSD, La Jolla, CA, USA.
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23
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Ray A, Rajian JR, Lee YEK, Wang X, Kopelman R. Lifetime-based photoacoustic oxygen sensing in vivo. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:057004. [PMID: 22612143 PMCID: PMC3381016 DOI: 10.1117/1.jbo.17.5.057004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/16/2012] [Accepted: 03/29/2012] [Indexed: 05/18/2023]
Abstract
The determination of oxygen levels in blood and other tissues in vivo is critical for ensuring proper body functioning, for monitoring the status of many diseases, such as cancer, and for predicting the efficacy of therapy. Here we demonstrate, for the first time, a lifetime-based photoacoustic technique for the measurement of oxygen in vivo, using an oxygen sensitive dye, enabling real time quantification of blood oxygenation. The results from the main artery in the rat tail indicated that the lifetime of the dye, quantified by the photoacoustic technique, showed a linear relationship with the blood oxygenation levels in the targeted artery.
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Affiliation(s)
- Aniruddha Ray
- University of Michigan, Biophysics, Ann Arbor, Michigan 48109
| | | | - Yong-Eun Koo Lee
- University of Michigan, Department of Chemistry, Ann Arbor, Michigan 48109
| | - Xueding Wang
- University of Michigan, Department of Radiology, Ann Arbor, Michigan 48109
- Address all correspondence to: Xueding Wang, University of Michigan, Department of Radiology, Ann Arbor, Michigan 48109. E-mail: ; Raoul Kopelman, University of Michigan, Biophysics, Ann Arbor, Michigan 48109. Tel: +1 734 764 7541; Fax: +1 734 936 2778; E-mail:
| | - Raoul Kopelman
- University of Michigan, Biophysics, Ann Arbor, Michigan 48109
- University of Michigan, Department of Chemistry, Ann Arbor, Michigan 48109
- Address all correspondence to: Xueding Wang, University of Michigan, Department of Radiology, Ann Arbor, Michigan 48109. E-mail: ; Raoul Kopelman, University of Michigan, Biophysics, Ann Arbor, Michigan 48109. Tel: +1 734 764 7541; Fax: +1 734 936 2778; E-mail:
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Moriggi L, Yaseen MA, Helm L, Caravan P. Serum albumin targeted, pH-dependent magnetic resonance relaxation agents. Chemistry 2012; 18:3675-86. [PMID: 22328098 PMCID: PMC3304010 DOI: 10.1002/chem.201103344] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Indexed: 11/11/2022]
Abstract
The objective of this work was the synthesis of serum albumin targeted, Gd(III)-based magnetic resonance imaging (MRI) contrast agents exhibiting a strong pH-dependent relaxivity. Two new complexes (Gd-glu and Gd-bbu) were synthesized based on the DO3A macrocycle modified with three carboxyalkyl substituents α to the three ring nitrogen atoms, and a biphenylsulfonamide arm. The sulfonamide nitrogen coordinates the Gd in a pH-dependent fashion, resulting in a decrease in the hydration state, q, as pH is increased and a resultant decrease in relaxivity (r(1)). In the absence of human serum albumin (HSA), r(1) increases from 2.0 to 6.0 mM(-1) s(-1) for Gd-glu and from 2.4 to 9.0 mM(-1) s(-1) for Gd-bbu from pH 5 to 8.5 at 37 °C, 0.47 T, respectively. These complexes (0.2 mM) are bound (>98.9 %) to HSA (0.69 mM) over the pH range 5-8.5. Binding to albumin increases the rotational correlation time and results in higher relaxivity. The r(1) increased 120 % (pH 5) and 550 % (pH 8.5) for Gd-glu and 42 % (pH 5) and 260 % (pH 8.5) for Gd-bbu. The increases in r(1) at pH 5 were unexpectedly low for a putative slow tumbling q=2 complex. The Gd-bbu system was investigated further. At pH 5, it binds in a stepwise fashion to HSA with dissociation constants K(d1)=0.65, K(d2)=18, K(d3)=1360 μM. The relaxivity at each binding site was constant. Luminescence lifetime titration experiments with the Eu(III) analogue revealed that the inner-sphere water ligands are displaced when the complex binds to HSA resulting in lower than expected r(1) at pH 5. Variable pH and temperature nuclear magnetic relaxation dispersion (NMRD) studies showed that the increased r(1) of the albumin-bound q=0 complexes is due to the presence of a nearby water molecule with a long residency time (1-2 ns). The distance between this water molecule and the Gd ion changes with pH resulting in albumin-bound pH-dependent relaxivity.
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Affiliation(s)
- Loïck Moriggi
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129 (USA)
| | - Mohammad A. Yaseen
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129 (USA)
| | - Lothar Helm
- Institut de Chimie Moléculaire et Biologique, Ecole Polytechnique Fédérale de Lausanne, EPFL-BCH, 1015 Lausanne (Switzerland)
| | - Peter Caravan
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129 (USA)
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25
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Optical probes and techniques for O2 measurement in live cells and tissue. Cell Mol Life Sci 2012; 69:2025-39. [PMID: 22249195 PMCID: PMC3371327 DOI: 10.1007/s00018-011-0914-0] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 12/19/2011] [Accepted: 12/29/2011] [Indexed: 01/03/2023]
Abstract
In recent years, significant progress has been achieved in the sensing and imaging of molecular oxygen (O2) in biological samples containing live cells and tissue. We review recent developments in the measurement of O2 in such samples by optical means, particularly using the phosphorescence quenching technique. The main types of soluble O2 sensors are assessed, including small molecule, supramolecular and particle-based structures used as extracellular or intracellular probes in conjunction with different detection modalities and measurement formats. For the different O2 sensing systems, particular attention is paid to their merits and limitations, analytical performance, general convenience and applicability in specific biological applications. The latter include measurement of O2 consumption rate, sample oxygenation, sensing of intracellular O2, metabolic assessment of cells, and O2 imaging of tissue, vasculature and individual cells. Altogether, this gives the potential user a comprehensive guide for the proper selection of the appropriate optical probe(s) and detection platform to suit their particular biological applications and measurement requirements.
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26
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Hosny NA, Lee DA, Knight MM. Single photon counting fluorescence lifetime detection of pericellular oxygen concentrations. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:016007. [PMID: 22352657 DOI: 10.1117/1.jbo.17.1.016007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Fluorescence lifetime imaging microscopy offers a non-invasive method for quantifying local oxygen concentrations. However, existing methods are either invasive, require custom-made systems, or show limited spatial resolution. Therefore, these methods are unsuitable for investigation of pericellular oxygen concentrations. This study describes an adaptation of commercially available equipment which has been optimized for quantitative extracellular oxygen detection with high lifetime accuracy and spatial resolution while avoiding systematic photon pile-up. The oxygen sensitive fluorescent dye, tris(2,2'-bipyridyl)ruthenium(II) chloride hexahydrate [Ru(bipy)(3)](2+), was excited using a two-photon excitation laser. Lifetime was measured using a Becker & Hickl time-correlated single photon counting, which will be referred to as a TCSPC card. [Ru(bipy)(3)](2+) characterization studies quantified the influences of temperature, pH, cellular culture media and oxygen on the fluorescence lifetime measurements. This provided a precisely calibrated and accurate system for quantification of pericellular oxygen concentration based on measured lifetimes. Using this technique, quantification of oxygen concentrations around isolated viable chondrocytes, seeded in three-dimensional agarose gel, revealed a subpopulation of cells that exhibited significant spatial oxygen gradients such that oxygen concentration reduced with increasing proximity to the cell. This technique provides a powerful tool for quantifying spatial oxygen gradients within three-dimensional cellular models.
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Affiliation(s)
- Neveen A Hosny
- University of London, School of Engineering and Materials Science, Queen Mary, London, United Kingdom, E1 4NS.
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27
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28
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Devor A, Boas DA, Einevoll GT, Buxton RB, Dale AM. Neuronal Basis of Non-Invasive Functional Imaging: From Microscopic Neurovascular Dynamics to BOLD fMRI. NEURAL METABOLISM IN VIVO 2012. [DOI: 10.1007/978-1-4614-1788-0_15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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"Overshoot" of O₂ is required to maintain baseline tissue oxygenation at locations distal to blood vessels. J Neurosci 2011; 31:13676-81. [PMID: 21940458 DOI: 10.1523/jneurosci.1968-11.2011] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In vivo imaging of cerebral tissue oxygenation is important in defining healthy physiology and pathological departures associated with cerebral disease. We used a recently developed two-photon microscopy method, based on a novel phosphorescent nanoprobe, to image tissue oxygenation in the rat primary sensory cortex in response to sensory stimulation. Our measurements showed that a stimulus-evoked increase in tissue pO₂ depended on the baseline pO₂ level. In particular, during sustained stimulation, the steady-state pO₂ at low-baseline locations remained at the baseline, despite large pO₂ increases elsewhere. In contrast to the steady state, where pO₂ never decreased below the baseline, transient decreases occurred during the "initial dip" and "poststimulus undershoot." These results suggest that the increase in blood oxygenation during the hemodynamic response, which has been perceived as a paradox, may serve to prevent a sustained oxygenation drop at tissue locations that are remote from the vascular feeding sources.
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30
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Davis MA, Shams Kazmi SM, Ponticorvo A, Dunn AK. Depth dependence of vascular fluorescence imaging. BIOMEDICAL OPTICS EXPRESS 2011; 2:3349-62. [PMID: 22162824 PMCID: PMC3233253 DOI: 10.1364/boe.2.003349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/01/2011] [Accepted: 11/15/2011] [Indexed: 05/19/2023]
Abstract
In vivo surface imaging of fluorescently labeled vasculature has become a widely used tool for functional brain imaging studies. Techniques such as phosphorescence quenching for oxygen tension measurements and indocyanine green fluorescence for vessel perfusion monitoring rely on surface measurements of vascular fluorescence. However, the depth dependence of the measured fluorescence signals has not been modeled in great detail. In this paper, we investigate the depth dependence of the measured signals using a three-dimensional Monte Carlo model combined with high resolution vascular anatomy. We found that a bulk-vascularization assumption to modeling the depth dependence of the signal does not provide an accurate picture of penetration depth of the collected fluorescence signal in most cases. Instead the physical distribution of microvasculature, the degree of absorption difference between extravascular and intravascular space, and the overall difference in absorption at the excitation and emission wavelengths must be taken into account to determine the depth penetration of the fluorescence signal. Additionally, we found that using targeted illumination can provide for superior surface vessel sensitivity over wide-field illumination, with small area detection offering an even greater amount of sensitivity to surface vasculature. Depth sensitivity can be enhanced by either increasing the detector area or increasing the illumination area. Finally, we see that excitation wavelength and vessel size can affect intra-vessel sampling distribution, as well as the amount of signal that originates from inside the vessel under targeted illumination conditions.
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Affiliation(s)
- Mitchell A. Davis
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712,
USA
| | - S. M. Shams Kazmi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712,
USA
| | - Adrien Ponticorvo
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712,
USA
| | - Andrew K. Dunn
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712,
USA
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31
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Esipova TV, Karagodov A, Miller J, Wilson DF, Busch TM, Vinogradov SA. Two new "protected" oxyphors for biological oximetry: properties and application in tumor imaging. Anal Chem 2011; 83:8756-65. [PMID: 21961699 DOI: 10.1021/ac2022234] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We report the synthesis, calibration, and examples of application of two new phosphorescent probes, Oxyphor R4 and Oxyphor G4, optimized specifically for in vivo oxygen imaging by phosphorescence quenching. These "protected" dendritic probes can operate in either albumin-rich (blood plasma) or albumin-free (interstitial space) environments at all physiological oxygen concentrations, from normoxic to deep hypoxic conditions. Oxyphors R4 and G4 are derived from phosphorescent Pd-meso-tetra-(3,5-dicarboxyphenyl)-porphyrin (PdP) or Pd-meso-tetra-(3,5-dicarboxyphenyl)-tetrabenzoporphyrin (PdTBP), respectively, and possess features common for protected dendritic probes, i.e., hydrophobic dendritic encapsulation of phosphorescent metalloporphyrins and hydrophilic PEGylated periphery. The new Oxyphors are highly soluble in aqueous environments and do not permeate biological membranes. The probes were calibrated under physiological conditions (pH 6.4-7.8) and temperatures (22-38 °C), showing high stability, reproducibility of signals, and lack of interactions with biological solutes. Oxyphor G4 was used to dynamically image intravascular and interstitial oxygenation in murine tumors in vivo. The physiological relevance of the measurements was demonstrated by dynamically recording changes in tissue oxygenation during application of anesthesia (isofluorane). These experiments revealed that changes in isofluorane concentration significantly affect tissue oxygenation.
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Affiliation(s)
- Tatiana V Esipova
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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32
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Sakadžić S, Roussakis E, Yaseen MA, Mandeville ET, Srinivasan VJ, Arai K, Ruvinskaya S, Wu W, Devor A, Lo EH, Vinogradov SA, Boas DA. Cerebral blood oxygenation measurement based on oxygen-dependent quenching of phosphorescence. J Vis Exp 2011:1694. [PMID: 21587157 DOI: 10.3791/1694] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Monitoring of the spatiotemporal characteristics of cerebral blood and tissue oxygenation is crucial for better understanding of the neuro-metabolic-vascular relationship. Development of new pO2 measurement modalities with simultaneous monitoring of pO2 in larger fields of view with higher spatial and/or temporal resolution will enable greater insight into the functioning of the normal brain and will also have significant impact on diagnosis and treatment of neurovascular diseases such as stroke, Alzheimer's disease, and head injury. Optical imaging modalities have shown a great potential to provide high spatiotemporal resolution and quantitative imaging of pO2 based on hemoglobin absorption in visible and near infrared range of optical spectrum. However, multispectral measurement of cerebral blood oxygenation relies on photon migration through the highly scattering brain tissue. Estimation and modeling of tissue optical parameters, which may undergo dynamic changes during the experiment, is typically required for accurate estimation of blood oxygenation. On the other hand, estimation of the partial pressure of oxygen (pO2) based on oxygen-dependent quenching of phosphorescence should not be significantly affected by the changes in the optical parameters of the tissue and provides an absolute measure of pO2. Experimental systems that utilize oxygen-sensitive dyes have been demonstrated in in vivo studies of the perfused tissue as well as for monitoring the oxygen content in tissue cultures, showing that phosphorescence quenching is a potent technology capable of accurate oxygen imaging in the physiological pO2 range. Here we demonstrate with two different imaging modalities how to perform measurement of pO2 in cortical vasculature based on phosphorescence lifetime imaging. In first demonstration we present wide field of view imaging of pO2 at the cortical surface of a rat. This imaging modality has relatively simple experimental setup based on a CCD camera and a pulsed green laser. An example of monitoring the cortical spreading depression based on phosphorescence lifetime of Oxyphor R3 dye was presented. In second demonstration we present a high resolution two-photon pO2 imaging in cortical micro vasculature of a mouse. The experimental setup includes a custom built 2-photon microscope with femtosecond laser, electro-optic modulator, and photon-counting photo multiplier tube. We present an example of imaging the pO2 heterogeneity in the cortical microvasculature including capillaries, using a novel PtP-C343 dye with enhanced 2-photon excitation cross section.
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Affiliation(s)
- Sava Sakadžić
- Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, USA
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33
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Lee YEK, Ulbrich EE, Kim G, Hah H, Strollo C, Fan W, Gurjar R, Koo S, Kopelman R. Near infrared luminescent oxygen nanosensors with nanoparticle matrix tailored sensitivity. Anal Chem 2011; 82:8446-55. [PMID: 20849084 DOI: 10.1021/ac1015358] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The development of sensors for noninvasive determination of oxygen levels in live cells and tissues is critical for the understanding of cellular functions, as well as for monitoring the status of disease, such as cancer, and for predicting the efficacy of therapy. We describe such nontoxic, targeted, and ratiometric 30 nm oxygen nanosensors made of polyacrylamide hydrogel, near-infrared (NIR) luminescent dyes, and surface-conjugated tumor-specific peptides. They enabled noninvasive real-time monitoring of oxygen levels in live cancer cells under normal and hypoxic conditions. The required sensitivity, brightness, selectivity, and stability were achieved by tailoring the interaction between the nanomatrix and indicator dyes. The developed nanosensors may become useful for in vivo oxygen measurements.
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Affiliation(s)
- Yong-Eun Koo Lee
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
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34
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Yaseen MA, Srinivasan VJ, Sakadžić S, Radhakrishnan H, Gorczynska I, Wu W, Fujimoto JG, Boas DA. Microvascular oxygen tension and flow measurements in rodent cerebral cortex during baseline conditions and functional activation. J Cereb Blood Flow Metab 2011; 31:1051-63. [PMID: 21179069 PMCID: PMC3070982 DOI: 10.1038/jcbfm.2010.227] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/17/2010] [Accepted: 11/26/2010] [Indexed: 12/13/2022]
Abstract
Measuring cerebral oxygen delivery and metabolism microscopically is important for interpreting macroscopic functional magnetic resonance imaging (fMRI) data and identifying pathological changes associated with stroke, Alzheimer's disease, and brain injury. Here, we present simultaneous, microscopic measurements of cerebral blood flow (CBF) and oxygen partial pressure (pO(2)) in cortical microvessels of anesthetized rats under baseline conditions and during somatosensory stimulation. Using a custom-built imaging system, we measured CBF with Fourier-domain optical coherence tomography (OCT), and vascular pO(2) with confocal phosphorescence lifetime microscopy. Cerebral blood flow and pO(2) measurements displayed heterogeneity over distances irresolvable with fMRI and positron emission tomography. Baseline measurements indicate O(2) extraction from pial arterioles and homogeneity of ascending venule pO(2) despite large variation in microvessel flows. Oxygen extraction is linearly related to flow in ascending venules, suggesting that flow in ascending venules closely matches oxygen demand of the drained territory. Oxygen partial pressure and relative CBF transients during somatosensory stimulation further indicate arteriolar O(2) extraction and suggest that arterioles contribute to the fMRI blood oxygen level dependent response. Understanding O(2) supply on a microscopic level will yield better insight into brain function and the underlying mechanisms of various neuropathologies.
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Affiliation(s)
- Mohammad A Yaseen
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Vivek J Srinivasan
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Sava Sakadžić
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Harsha Radhakrishnan
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Iwona Gorczynska
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Weicheng Wu
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - David A Boas
- Department of Radiology, MGH/MIT/HMS Athinuola A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
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35
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Wang Y, Hu S, Maslov K, Zhang Y, Xia Y, Wang LV. In vivo integrated photoacoustic and confocal microscopy of hemoglobin oxygen saturation and oxygen partial pressure. OPTICS LETTERS 2011; 36:1029-31. [PMID: 21478972 PMCID: PMC3076119 DOI: 10.1364/ol.36.001029] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We developed dual-modality microscope integrating photoacoustic microscopy (PAM) and fluorescence confocal microscopy (FCM) to noninvasively image hemoglobin oxygen saturation (sO₂) and oxygen partial pressure (pO₂) in vivo in single blood vessels with high spatial resolution. While PAM measures sO₂ by imaging hemoglobin optical absorption at two wavelengths, FCM quantifies pO₂ using phosphorescence quenching. The variations of sO₂ and pO₂ values in multiple orders of vessel branches under hyperoxic (100% oxygen) and normoxic (21% oxygen) conditions correlate well with the oxygen-hemoglobin dissociation curve. In addition, the total concentration of hemoglobin is imaged by PAM at an isosbestic wavelength.
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36
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Sinks LE, Robbins GP, Roussakis E, Troxler T, Hammer DA, Vinogradov SA. Two-photon microscopy of oxygen: polymersomes as probe carrier vehicles. J Phys Chem B 2010; 114:14373-82. [PMID: 20462225 PMCID: PMC2939231 DOI: 10.1021/jp100353v] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oxygen concentration distributions in biological systems can be imaged by the phosphorescence quenching method in combination with two-photon laser scanning microscopy. In this paper, we identified the excitation regime in which the signal of a two-photon-enhanced phosphorescent probe (Finikova, O. S.; Lebedev, A. Y.; Aprelev, A.; Troxler, T.; Gao, F.; Garnacho, C.; Muro, S.; Hochstrasser, R. M.; Vinogradov, S. A. ChemPhysChem 2008, 9, 1673-1679) is dependent quadratically on the excitation power (quadratic regime), and performed simulations that relate the photophysical properties of the probe to the imaging resolution. Further, we characterized polymersomes as a method of probe encapsulation and delivery. Photophysical and oxygen sensing properties of the probe were found unchanged when the probe is encapsulated in polymersomes. Polymersomes were found capable of sustaining high probe concentrations, thereby serving to improve the signal-to-noise ratios for oxygen detection compared to the previously employed probe delivery methods. Imaging of polymersomes loaded with the probe was used as a test-bed for a new method.
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37
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Grist SM, Chrostowski L, Cheung KC. Optical oxygen sensors for applications in microfluidic cell culture. SENSORS (BASEL, SWITZERLAND) 2010; 10:9286-316. [PMID: 22163408 PMCID: PMC3230974 DOI: 10.3390/s101009286] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 09/17/2010] [Accepted: 10/10/2010] [Indexed: 01/09/2023]
Abstract
The presence and concentration of oxygen in biological systems has a large impact on the behavior and viability of many types of cells, including the differentiation of stem cells or the growth of tumor cells. As a result, the integration of oxygen sensors within cell culture environments presents a powerful tool for quantifying the effects of oxygen concentrations on cell behavior, cell viability, and drug effectiveness. Because microfluidic cell culture environments are a promising alternative to traditional cell culture platforms, there is recent interest in integrating oxygen-sensing mechanisms with microfluidics for cell culture applications. Optical, luminescence-based oxygen sensors, in particular, show great promise in their ability to be integrated with microfluidics and cell culture systems. These sensors can be highly sensitive and do not consume oxygen or generate toxic byproducts in their sensing process. This paper presents a review of previously proposed optical oxygen sensor types, materials and formats most applicable to microfluidic cell culture, and analyzes their suitability for this and other in vitro applications.
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Affiliation(s)
- Samantha M. Grist
- Department of Electrical & Computer Engineering, University of British Columbia/2332 Main Mall, Vancouver, BC V6T 1Z4, Canada; E-Mails: (L.C.); (K.C.C.)
| | - Lukas Chrostowski
- Department of Electrical & Computer Engineering, University of British Columbia/2332 Main Mall, Vancouver, BC V6T 1Z4, Canada; E-Mails: (L.C.); (K.C.C.)
| | - Karen C. Cheung
- Department of Electrical & Computer Engineering, University of British Columbia/2332 Main Mall, Vancouver, BC V6T 1Z4, Canada; E-Mails: (L.C.); (K.C.C.)
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38
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Vazquez AL, Masamoto K, Fukuda M, Kim SG. Cerebral oxygen delivery and consumption during evoked neural activity. FRONTIERS IN NEUROENERGETICS 2010; 2:11. [PMID: 20616881 PMCID: PMC2899518 DOI: 10.3389/fnene.2010.00011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 05/26/2010] [Indexed: 11/13/2022]
Abstract
Increases in neural activity evoke increases in the delivery and consumption of oxygen. Beyond observations of cerebral tissue and blood oxygen, the role and properties of cerebral oxygen delivery and consumption during changes in brain function are not well understood. This work overviews the current knowledge of functional oxygen delivery and consumption and introduces recent and preliminary findings to explore the mechanisms by which oxygen is delivered to tissue as well as the temporal dynamics of oxygen metabolism. Vascular oxygen tension measurements have shown that a relatively large amount of oxygen exits pial arterioles prior to capillaries. Additionally, increases in cerebral blood flow (CBF) induced by evoked neural activation are accompanied by arterial vasodilation and also by increases in arteriolar oxygenation. This increase contributes not only to the down-stream delivery of oxygen to tissue, but also to delivery of additional oxygen to extra-vascular spaces surrounding the arterioles. On the other hand, the changes in tissue oxygen tension due to functional increases in oxygen consumption have been investigated using a method to suppress the evoked CBF response. The functional decreases in tissue oxygen tension induced by increases in oxygen consumption are slow to evoked changes in CBF under control conditions. Preliminary findings obtained using flavoprotein autofluorescence imaging suggest cellular oxidative metabolism changes at a faster rate than the average changes in tissue oxygen. These issues are important in the determination of the dynamic changes in tissue oxygen metabolism from hemoglobin-based imaging techniques such as blood oxygenation-level dependent functional magnetic resonance imaging (fMRI).
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Affiliation(s)
- Alberto L Vazquez
- Department of Radiology, University of Pittsburgh Pittsburgh, PA, USA
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