Direct and Sensitized Photooxidation of Cyanine Dyes

Byers, Gary W.; Gross, Stanley J.; Henrichs, P. M.

doi:10.1111/j.1751-1097.1976.tb06768.x

Cited by 98 publications

(74 citation statements)

References 26 publications

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“…2), the dye itself consumed oxygen and was gradually bleached. At least part of this effect is attributed to photooxidation of the dye by 102 (22). It is conceivable, however, that in the presence of membranes (Fig.…”

Section: Discussionmentioning

confidence: 93%

Photodynamic action of merocyanine 540 on artificial and natural cell membranes: involvement of singlet molecular oxygen.

Kalyanaraman¹,

Feix²,

Sieber³

et al. 1987

Proc. Natl. Acad. Sci. U.S.A.

134

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The photochemistry of merocyanine 540 (MC 540), a sensitizing dye that binds preferentially to leukemia and electrically excitable cells, has been investigated. MC 540-mediated photooxidation of histidine, arachidonate, and unsaturated phospholipid vesicles was assessed by spin label oximetry and shown to involve type II (singlet oxygen) chemistry. The dye was also shown to be a potent sensitizer of lipid peroxidation in a natural cell membrane, the erythrocyte ghost. Inhibition by azide, stimulation by 2H20, and identification of the cholesterol product 5a-cholest-6-ene-3,8,5-diol in this system, all were consistent with singlet oxygen intermediacy. Finally, MC 540 was found to be considerably more phototoxic to-K-562 leukemia cells in 2H20 than in H20. We conclude that singlet oxygen plays a major role in the phototherapeutic effects of this dye. (4)(5)(6)(7)(8). In this way leukemic cells have been selectively purged from bone marrow in vitro, and attempts to exploit this differential photosensitivity in clinical situations are underway (9).Although the effectiveness of MC 540 in killing neoplastic cells has been demonstrated (5-8), little is known about the mechanism of cell killing, and those factors on which the selectivity of MC 540 for cancer cells is based are not understood. However, the fact that uptake and toxicity of MC 540 in leukemic cells are augmented in the presence of visible light and oxygen (2) suggests that photodynamic processes are involved. A preliminary report has indicated that singlet oxygen (102) is one of the reactive intermediates (10). The first detectable event following the production of this species is rapid consumption of molecular oxygen, which can occur as a result of reactions with biological constituents. Thus, we have used the highly sensitive spin label oximetric approach (11, 12) to monitor oxygen consumption during MC 540-sensitive photooxidation. Using this approach, we now report additional evidence for the production of 102 by the photoactivated dye. The involvement of 102 in the killing of leukemic cells and in the peroxidation of cell membrane phospholipids and cholesterol is also reported. MATERIALS AND METHODSOximetry Studies Using Model Systems. Sample preparation. MC 540 obtained from Eastman was dissolved in a 50:50 mixture of ethanol and water and frozen until further use. Arachidonic acid (Sigma) was dissolved in ethanol. All other chemicals were used as received.Sample irradiation. Samples for irradiation typically contained 90 ,uM MC 540 in deionized water, pH 7.0. 3-Carbamoyl-2,2,5,5-tetramethyl-3-pyrrolin-1-yloxy(CTPO; Aldrich) was added to give a final concentration of 1.2 X 10-4 M. Samples, following saturation with a mixture of 50% nitrogen and 50% air from calibrated flow meters (Matheson) were introduced into a Pasteur pipette, which was sealed with capillary tube sealant (Miniseal, American Scientific Products, Stone Mountain, GA) and subsequently positioned inside the electron spin resonance (ESR) cavity.Samples were irradiated in the ES...

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Section: Discussionmentioning

confidence: 93%

Photodynamic action of merocyanine 540 on artificial and natural cell membranes: involvement of singlet molecular oxygen.

Kalyanaraman¹,

Feix²,

Sieber³

et al. 1987

Proc. Natl. Acad. Sci. U.S.A.

134

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“…Several products can result from the oxidation of I (14). For elucidating the essential properties of the complex to activate H 2 O 2 in basic solution this information is not essential.…”

Section: Substrate Selectionmentioning

confidence: 97%

Activation of Hydrogen Peroxide for Oxidation by Copper(II) Complexes

Robbins

Drago

1997

Journal of Catalysis

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“…Light-induced decomposition of the dye could produce a more hydrophilic cation (Byers, Gross & Henrichs, 1976), which would be pulled by dielectric image forces toward the adjacent aqueous solution, creating the electric displacement required for the rising part of the photo-voltage. The applied voltage would modify the dye's position before decomposition, and thereby modify the waveform risetime.…”

Section: ) Light-induced Charge Rearrangements In the Dye This Mechmentioning

confidence: 99%

Cyanine dye structural and voltage-induced variations in photo-voltages of bilayer membranes

Huebner

1978

J. Membrain Biol.

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Flash illumination alters the voltage across bilayer lipid membranes in the presence of certain cyanine dyes. The waveforms of the photo-voltage vary systematically with dye structure and imposed transmembrane voltage. Experimental results are reported for 27 positively charged cyanine dyes, primarily oxazole derivatives, using lecithin/oxidized cholesterol bilayer membranes and 10-mM sodium chloride solutions. Several dyes do not induce any photo-voltages. Examples are 3,3' diethyl 9 ethyl 2,2' oxacarbocyanine iodide, 3,3' diethyl 2 oxa 2" thiacyanine iodide, and 3,3' dimethyl 2,2' indocarbocyanine iodide. Several dyes, when added to one side of the membranes, induce monophasic waveforms. Examples are 3,3' dimethyl 2,2' oxacarbocyanine chloride, and 3,4,3',4' tetramethyl 2,2' oxazalinocarbocyanine iodide. Other dyes induce a photo-voltage only if transmembrane voltages are imposed. These waveforms are biphasic with some dyes (3,3' diethyl 2,2' oxacarbocyanine iodide, for example) and monophasic with other dyes (3,3' dibutyl 2,2' oxacarbocyanine iodide, for example). The photo-voltage waveforms are explained by models that consider the movement of charged dye molecules within the membrane, following optical excitation. The dye movements are probably induced through charge rearrangements in the dye associated with long-lived triplet states, isomerization, or through excimer formation. These results provide information on the location and orientation of the dye molecules within bilayer membranes. The variations which occur in the waveforms with applied voltage indicate that these membranes are fluid in the direction perpendicular to the membrane plane.

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Direct and Sensitized Photooxidation of Cyanine Dyes

Cited by 98 publications

References 26 publications

Photodynamic action of merocyanine 540 on artificial and natural cell membranes: involvement of singlet molecular oxygen.

Photodynamic action of merocyanine 540 on artificial and natural cell membranes: involvement of singlet molecular oxygen.

Activation of Hydrogen Peroxide for Oxidation by Copper(II) Complexes

Cyanine dye structural and voltage-induced variations in photo-voltages of bilayer membranes

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