Oxyphor R2 and G2: phosphors for measuring oxygen by oxygen-dependent quenching of phosphorescence

Dunphy, Isolde; Vinogradov, Sergei A.; Wilson, David F.

doi:10.1016/s0003-2697(02)00384-6

Cited by 264 publications

(273 citation statements)

References 24 publications

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“…2B. Calibration constants were determined to be k q ϭ 267 mmHg/s and 0 ϭ 252 s. Those calibration constants are in agreement with previously reported values (2,6).…”

Section: Resultssupporting

confidence: 89%

“…Over a broad range of pathophysiological conditions conversion of vPO 2 to vHbO 2 will not be severely affected by this pH dependency. In this context, it is also important to note that the quenching constants of Oxyphor G2 are pH independent (2).…”

Section: Resultsmentioning

confidence: 99%

“…The phosphor-albumin complex is well confined to the circulation (14) and emits phosphorescence with a wavelength ϳ800 nm (i.e., infrared light) if excited with light of a wavelength ϳ630 nm (i.e., red light). The lifetime of the phosphorescence is oxygen dependent (2) and is quantitatively related to the oxygen level by the Stern-Volmer relationship…”

Section: Methodsmentioning

confidence: 99%

“…This has led to a new generation of phosphors for oxygen measurements with favor-able spectral properties. Oxyphor G2, for example, is a watersoluble phosphor with excitation and emission wavelengths in the (near-)infrared spectrum (2). This allows much deeper tissue penetration because of the low absorbance of tissue in this so-called "tissue optical window" (12,16).…”

mentioning

confidence: 99%

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Monitoring of renal venous Po₂and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

Mik

Johannes

İnce³

2008

American Journal of Physiology-Renal Physiology

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Mik EG, Johannes T, Ince C. Monitoring of renal venous PO2 and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique. Am J Physiol Renal Physiol 294: F676-F681, 2008. First published January 9, 2008 doi:10.1152 doi:10. /ajprenal.00569.2007 is an important parameter that has been shown to be influenced by various pathophysiological circumstances. V O2,ren has to be repeatedly measured during an experiment to gain insight in the dynamics of (dys)regulation of oxygen metabolism. In small animals, the classical approach of blood gas analysis of arterial and venous blood samples is only limitedly applicable due to fragile vessels and a low circulating blood volume. We present a phosphorescence lifetime technique that allows nearcontinuous measurement of renal venous PO2 (vPO2) and V O2,ren in rats. The technique does not rely on penetration of the blood vessel, but uses a small reflection probe. This probe is placed in close proximity to the renal vein for detection of the oxygen-dependent phosphorescence of the injected water-soluble near-infrared phosphor Oxyphor G2. The technique was calibrated in vitro and the calibration constants were validated in vivo in anesthetized and mechanically ventilated male Wistar rats. The hemoglobin saturation curve and its pH dependency were determined for calculation of renal venous oxygen content. The phosphorescence technique was in good agreement with blood gas analysis of renal venous blood samples, for both PO2 and hemoglobin saturation. To demonstrate its feasibility in practice, the technique was used in four rats during endotoxin infusion (10 mg ⅐ kg Ϫ1 ⅐ h Ϫ1 during 1 h). Renal vPO2 reduced by 40% upon reduction in oxygen delivery to 30% of baseline, but V O2 remained unchanged. This study documents the feasibility of near-continuous, nondestructive measurement of renal vPO 2 and V O2 by oxygendependent quenching of phosphorescence.oxygen-dependent quenching; Oxyphor G2; time-resolved spectroscopy; Pd-porphyrin THE MEASUREMENT OF OXYGEN in blood within arteries and veins is mandatory for the study of oxygen supply and demand of organs. For example, the oxygen delivery (DO 2 ) to an organ is calculated by the arterial oxygen content of the blood per volume times the blood flow to the organ. To also determine the oxygen utilization (V O 2 ) by an organ, the venous oxygen content has to be known. Another example of a situation where knowledge of the venous oxygenation over time is necessary is monitoring of the "PO 2 -gap," i.e., the discrepancy between capillary PO 2 and venous PO 2 when the capillary PO 2 drops below the venous PO 2 (9,22,23). The latter occurs under certain pathophysiological conditions, such as sepsis and shock (5), and is a valuable parameter when studying resuscitation protocols and treatments.

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“…2B. Calibration constants were determined to be k q ϭ 267 mmHg/s and 0 ϭ 252 s. Those calibration constants are in agreement with previously reported values (2,6).…”

Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Monitoring of renal venous Po₂and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

Mik

Johannes

İnce³

2008

American Journal of Physiology-Renal Physiology

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“…Phosphorescent complexes like platinum(II) and palladium(II) porphyrins could realize red light excitation by enlarge the conjugated structures 7, 8, 11. However it is difficult to extend the excitation wavelength to the NIR region.…”

Section: Introductionmentioning

confidence: 99%

A Phosphorescent Iridium(III) Complex‐Modified Nanoprobe for Hypoxia Bioimaging Via Time‐Resolved Luminescence Microscopy

Yang

et al. 2015

Advanced Science

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Oxygen plays a crucial role in many biological processes. Accurate monitoring of oxygen level is important for diagnosis and treatment of diseases. Autofluorescence is an unavoidable interference in luminescent bioimaging, so that an amount of research work has been devoted to reducing background autofluorescence. Herein, a phosphorescent iridium(III) complex‐modified nanoprobe is developed, which can monitor oxygen concentration and also reduce autofluorescence under both downconversion and upconversion channels. The nanoprobe is designed based on the mesoporous silica coated lanthanide‐doped upconversion nanoparticles, which contains oxygen‐sensitive iridium(III) complex in the outer silica shell. To image intracellular hypoxia without the interferences of autofluorescence, time‐resolved luminescent imaging technology and near‐infrared light excitation, both of which can reduce autofluorescence effectively, are adopted in this work. Moreover, gradient O2 concentration can be detected clearly through confocal microscopy luminescence intensity imaging, phosphorescence lifetime imaging microscopy, and time‐gated imaging, which is meaningful to oxygen sensing in tissues with nonuniform oxygen distribution.

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Dendrimers

Svenson¹

2006

Kirk-Othmer Encyclopedia of Chemical Technology

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Dendritic polymers (dendrimers) are synthesized in a layer‐by‐layer fashion around a core molecule. Depending on the number of chemical functionalities and the shape of the core, dendrimers of various shapes and complexities can be produced with very low polydispersity. The high level of control over the architecture of dendrimers, their size, shape, branching length and density, and their surface functionality, makes these compounds ideal materials in medical and technical applications, such as drug delivery, gene transfection, imaging, luminescence, quantum dot stabilization, catalysis and waste remediation. The active agents may either be encapsulated into the interior of the dendrimers or they can be chemically attached or physically adsorbed onto the dendrimer surface, with the option to tailor the properties of the dendritic carrier to the specific needs of the active material in its specific applications. Surface modified dendrimers themselves may act as nanodrugs against tumors, bacteria, and viruses. Recent successes in simplifying the synthesis of dendrimers, such as the “lego” and “click” approaches, have provided a vastly expanded variety of dendritic compounds, while at the same time reducing the cost of their production.

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Oxyphor R2 and G2: phosphors for measuring oxygen by oxygen-dependent quenching of phosphorescence

Cited by 264 publications

References 24 publications

Monitoring of renal venous Po₂and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

Monitoring of renal venous Po₂and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

A Phosphorescent Iridium(III) Complex‐Modified Nanoprobe for Hypoxia Bioimaging Via Time‐Resolved Luminescence Microscopy

Dendrimers

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Oxyphor R2 and G2: phosphors for measuring oxygen by oxygen-dependent quenching of phosphorescence

Cited by 264 publications

References 24 publications

Monitoring of renal venous Po2and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

Monitoring of renal venous Po2and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

A Phosphorescent Iridium(III) Complex‐Modified Nanoprobe for Hypoxia Bioimaging Via Time‐Resolved Luminescence Microscopy

Dendrimers

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Monitoring of renal venous Po₂and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique

Monitoring of renal venous Po₂and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique