A comparative study of the photosensitizing characteristics of some cyanine dyes

Delaey, Els; Laar, Frederik van; Vos, Dirk De; Kamuhabwa, Appolinary; Jacobs, Pierre; Witte, Peter de

doi:10.1016/s1011-1344(00)00021-x

Cited by 253 publications

(204 citation statements)

References 31 publications

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“…Measurements of the quantum yield of singlet-oxygen generation by A2E or quantum yields of intersystem crossing of A2E indicate relatively modest singletoxygen production when measured in polar solvents and when compared to the performance of photosensitizers used in photodynamic therapy. These findings are consistent with the concept that the destructive capacity of the photoreactive process is compounded by the photoproducts generated when A2E is oxidized (Bunting, 1992;Delaey et al, 2000;Krieg et al, 1993). Also of significance to this discussion however, are spectroscopic studies indicating that the retinoid-derived side-arms of intracellular A2E are located in an apolar milieu, most likely at the hydrophobic interior of intracellular membranes (Sparrow et al, 1999).…”

Section: Discussionsupporting

confidence: 85%

Mechanisms involved in A2E oxidation

Kim

Jockusch

Itagaki

et al. 2008

Experimental Eye Research

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A2E is one of the bis-retinoid pyridinium compounds that accumulate as lipofuscin pigments in retinal pigment epithelial (RPE) cells in association with aging and in some inherited forms of retinal degeneration. Here we observed that 430 nm irradiation of A2E in the presence of the spin trap DMPO, led to the appearance of a superoxide dismutase-inhibitable electron paramagnetic resonance (EPR) spectrum characteristic of DMPO-OH; this finding was indicative of hydroxyl radical (OH) formation following initial spin trapping of superoxide anion by DMPO. We also observed an increase in dihydroethidium (HEt) fluorescence and luminol-based chemiluminescence that on the basis of inhibition by superoxide dismutase, was indicative of superoxide anion generation when A2E was irradiated at 430 nm in cell-free systems. Nevertheless, while A2E was readily oxidized in the presence of a singlet oxygen generator, superoxide anion did not serve to oxidize A2E. Specifically, by HPLC quantitation and FAB-mass spectroscopy, there was no evidence of A2E oxidation when A2E was incubated with a superoxide anion generator (xanthine/xanthine oxidase) in a variety of solvents (100% PBS, 30% DMSO in PBS, 100% MeOH and CHCl 3 ) or in the presence of detergent. On the other hand, however, peroxy-A2E, an oxidized form of A2E with an endoperoxide moiety on the short-arm of the molecule, readily underwent further oxygen addition when incubated with xanthine/xanthine oxidase. Superoxide anion may be generated by irradiation of A2E but is not involved in the early events that oxidize A2E. Superoxide can contribute to the further oxidation of already-oxidized A2E.

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Section: Discussionsupporting

confidence: 85%

Mechanisms involved in A2E oxidation

Kim

Jockusch

Itagaki

et al. 2008

Experimental Eye Research

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“…The corresponding light dose (6.95 J/cm 2 ) is very similar to that used for the clinically approved PS porfimer sodium in comparable experiments (5 J/cm 2 ). 79 The IC50 values for all measurements are shown in Table 2 Table 2). 79 Since cisplatin has a lightindependent mode of action, the PI is not applicable for this compound.…”

Section: Introductionmentioning

confidence: 99%

“…79 The IC50 values for all measurements are shown in Table 2 Table 2). 79 Since cisplatin has a lightindependent mode of action, the PI is not applicable for this compound. 83 Complex 2 displayed a very promising lack of activity towards non-tumorigenic cells (MRC-5) as well as towards cancerous cells (HeLa) in the dark in the range of concentrations measured in this study (up to 100 μM), while still demonstrating a moderate toxicity (IC50 = 25.3 ± 4.7 μM) upon irradiation and a PI of at least 4.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization, and Biological Evaluation of New Ru(II) Polypyridyl Photosensitizers for Photodynamic Therapy

et al. 2014

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Two Ru(II) polypyridyl complexes, Ru(DIP)2(bdt) (1) and [Ru(dqpCO2Me)(ptpy)](2+) (2) (DIP = 4,7-diphenyl-1,10-phenanthroline, bdt = 1,2-benzenedithiolate, dqpCO2Me = 4-methylcarboxy-2,6-di(quinolin-8-yl)pyridine), ptpy = 4'-phenyl-2,2':6',2 -terpyridine) have been investigated as photosensitizers (PSs) for photodynamic therapy (PDT). In our experimental settings, the phototoxicity and phototoxic index (PI) of 2 (IC50(light): 25.3 M, 420 nm, 6.95 J/cm(2); PI >4) and particularly of 1 (IC50(light): 0.62 M, 420 nm, 6.95 J/cm(2); PI: 80) are considerably superior compared to the two clinically approved PSs porfimer sodium and 5-aminolevulinic acid. Cellular uptake and distribution of these complexes was investigated by confocal microscopy (1) and by inductively coupled plasma mass spectrometry (1 and 2). Their phototoxicity was also determined against the Gram-(+) Staphylococcus aureus and Gram-(-) Escherichia coli for potential antimicrobial PDT (aPDT) applications. Both complexes showed significant aPDT activity (420 nm, 8 J/cm(2)) against Gram-(+) (S. aureus; >6 log10 CFU reduction) and, for 2, also against Gram-(-) E. coli (>4 log10 CFU reduction). Two Ru(II) polypyridyl complexes, Ru(DIP)2(bdt) (1) and [Ru(dqpCO2Me)(ptpy)] 2+ (2) (DIP = 4,7-diphenyl-1,10-phenanthroline; bdt = 1,2-benzenedithiolate; dqpCO2Me = 4-methylcarboxy-2,6-di(quinolin-8-yl)pyridine); ptpy = 4'-phenyl-2,2':6',2''-terpyridine) have been investigated as photosensitizers (PSs) for photodynamic therapy (PDT). In our experimental settings, the phototoxicity and photo-index (PI) of 2 (IC50(light): 25.3 μM, 420 nm, 6.95 J/cm 2 ; PI: >4) and particularly of 1 (IC50(light): 0.62 μM, 420 nm, 6.95 J/cm 2 ; PI: 80) are considerably superior compared to the two clinically approved PSs porfimer sodium and 5-aminolevulinic. Cellular uptake and distribution of these complexes was investigated by confocal microscopy (1) and by inductively coupled plasma-mass spectrometry (1 and 2). Their phototoxicity was also determined against the Gram-(+) S. aureus and Gram-(−) E. coli for potential antimicrobial PDT (aPDT) applications. Both complexes showed significant aPDT activity (420 nm, 8 J/cm 2 ) against Gram-(+) (S. aureus; >6 log10 CFU reduction) and, for 2, also against Gram-(−) E. coli (>4 log10 CFU reduction). 3Introduction.

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“…Cyanine dyes have found various applications in different fields, such as antimicrobial agents [1][2][3][4], photographic sensitizers, heat developable photosensitizing materials [5][6][7], and color photography [8]. Cyanine dyes also used as optical recording materials [9][10][11][12][13][14][15], in manufacturing of blue filter to laminate of an organic electroluminescent element, and color filter showed highly pure light emission [16] and antioxidants [17].…”

Section: Introductionmentioning

confidence: 99%

Oxonium heterocyclic quinone in the synthesis of some cyanine dyes and their antimicrobial activity

Gomaa

2014

Eur. J. Chem.

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A comparative study of the photosensitizing characteristics of some cyanine dyes

Cited by 253 publications

References 31 publications

Mechanisms involved in A2E oxidation

Mechanisms involved in A2E oxidation

Synthesis, Characterization, and Biological Evaluation of New Ru(II) Polypyridyl Photosensitizers for Photodynamic Therapy

Oxonium heterocyclic quinone in the synthesis of some cyanine dyes and their antimicrobial activity

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