Phthalocyanine Fluorescence in Tumors During PDT

Moan, Johan Emelian; Anholt, Helle

doi:10.1111/j.1751-1097.1990.tb01726.x

Cited by 26 publications

(16 citation statements)

References 9 publications

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“…Over the past decade, they have also attracted attention as functional chromophores for applications as organic charge carriers in photocopiers [2], as laser light absorbers in data storage systems [3,4], as photoconductors in photovoltaic cells [5], and in electrochromic displays [6]. Moreover, particular derivatives are known to have potential as second-generation photosensitisers for photodynamic therapy (PDT) of cancer [7] because they show strong absorption of far-red light between 600 and 850 nm wavelength which has a greater penetration of tissue [8], and satisfactory photosensitisation of singlet oxygen [9].…”

Section: Introductionmentioning

confidence: 99%

Position isomer separation of non-peripheral substituted zinc dibenzo-di(3,4-pyrido)porphyrazines

Sakamoto

Kato

Cook

2001

J. Porphyrins Phthalocyanines

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ABSTRACT:The cyclotetramerisation products from the 1, 8-diazabicyclo[5,4,0]undec-7-ene catalysed reaction of a 1:1 mol mixture of 3,6-didecylphthalonitrile and 3,4-dicynopyridine in the presence of zinc chloride have been isolated by chromatography. The fractions comprise zinc octadecylphthalocyanine and compounds in which one, two, three and four pyridinoid rings replace the didecylbenzenoid moiety. The zinc bis(1,4-didecylbenzo)bis(3,4-pyrido)porphyrazine fraction was separated further into four sub-fractions and the components have been characterised by 400 MHz proton nuclear magnetic resonance spectroscopy, visible region spectroscopy, fluorescence spectroscopy and by cyclic voltammetry.

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Section: Introductionmentioning

confidence: 99%

Position isomer separation of non-peripheral substituted zinc dibenzo-di(3,4-pyrido)porphyrazines

Sakamoto

Kato

Cook

2001

J. Porphyrins Phthalocyanines

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“…All animals were treated with a total light dose of 50 J. The effect of varying the light delivery regimen was studied using a drug-light interval of 24 h as our previous work and that of others using AlSPc in normal liver (Bown et al, 1986), and small rodent tumours (Tralau et al, 1987;Moan and Anholt, 1990) had shown a more homogeneous drug fluorescence distribution at this DLI compared with shorter times. Drug light intervals of 1 and 3 h were studied with a fixed light delivery regimen of 100 mW, continuous.…”

Section: Oxygen Saturation Measurementsmentioning

confidence: 99%

Correlation of real-time haemoglobin oxygen saturation monitoring during photodynamic therapy with microvascular effects and tissue necrosis in normal rat liver

et al. 2004

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Photodynamic therapy (PDT) requires a photosensitising drug, light and oxygen. While it is known that the haemoglobin oxygen saturation (HbSat) can be altered by PDT, little has been done to correlate this with microvascular changes and the final biological effect. This report describes such studies on the normal liver of rats sensitised with aluminium disulphonated phthalocyanine. In total, 50 J of light at 670 nm, continuous or fractionated at 25 or 100 mW, was applied with a single laser fibre touching the liver surface. HbSat was monitored continuously 1.5 -5.0 mm from the laser fibre using visible light reflectance spectroscopy (VLRS). Vascular shutdown was assessed by fluorescein angiography 2À40 min after light delivery. Necrosis was measured at post mortem 3 days after PDT. In all treatment groups at a 1.5 mm separation, HbSat fell to zero with little recovery after light delivery. At 2.5 mm, HbSat also decreased during light delivery, except with fractionated light, but then recovered. The greatest recovery of fluorescein perfusion after PDT was seen using 25 mW, suggesting an ischaemia/reperfusion injury. Necrosis was more extensive after low power and fractionated light than with 100 mW, continuous illumination. We conclude that VLRS is a useful technique for monitoring HbSat, although the correlation between HbSat, fluorescein exclusion and necrosis varied markedly with the light delivery regimen used.

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“…This is inferred from the observation that only in this case did D 2 0 enhance the rate of fluorescence change (Figure 1) . Moan and Anholt (1990) have recently observed fast transient changes in A1PcS 2 fluorescence in tumours during PDT. Our measurements were made about 2 min after illumintion, a time at which these transient changes disappear, and thus are unlikely to contribute to the changes in A1Pc fluorescence reported in this paper.…”

Section: Discussionmentioning

confidence: 98%

The Effect of Fluoride on Photodynamic-induced Fluorescence Changes of Aluminium Phthalocyanine in Chinese Hamster Cells

Ben‐Hur

Nagelkerke

Dubbelman

et al. 1992

International Journal of Radiation Biology

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Fluence-dependent changes in the fluorescence of aluminium phthalocyanine (AlPc) were measured in Chinese hamster ovary (CHO) cells using digital fluorescence microscopy of single cells and spectrofluorimetry of cell suspensions. During illumination the fluorescence initially increased and later progressively decreased. In the presence of fluoride, which protects against phototoxicity of AlPc by forming a fluoroaluminium complex, there was no initial increase in fluorescence: it decreased about 10 times faster than in the absence of fluoride. Qualitatively similar results were observed using single-cell fluorescence microscopy, which also showed the dye to be mostly localized in cytoplasmic organelles and membranes. The pattern of localization did not change during illumination. Concomitant assays of dye extracted from cells revealed little photodegradation that could not account for the fluorescence changes. The absorption spectra of AlPc-loaded cells showed some aggregation of the dye prior to light exposure. During illumination the dye was initially monomerized and subsequently progressively reaggregated. In the presence of fluoride no monomerization was seen, and the aggregation proceeded at a much faster rate. It is concluded that the fluorescence changes are not due to major relocalization of AlPc in the cells, but to light-induced monomerization followed by reaggregation. The protective effect of fluoride may be due to the enhanced aggregation rate, because aggregated dye molecules are photochemically inactive. Because D2(0) affects neither the initial enhanced fluorescence in the absence of fluoride nor the rapid decrease in its presence it appears that 1O2 is not involved in the photodynamic reactions leading to these changes.

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Phthalocyanine Fluorescence in Tumors During PDT

Cited by 26 publications

References 9 publications

Position isomer separation of non-peripheral substituted zinc dibenzo-di(3,4-pyrido)porphyrazines

Position isomer separation of non-peripheral substituted zinc dibenzo-di(3,4-pyrido)porphyrazines

Correlation of real-time haemoglobin oxygen saturation monitoring during photodynamic therapy with microvascular effects and tissue necrosis in normal rat liver

The Effect of Fluoride on Photodynamic-induced Fluorescence Changes of Aluminium Phthalocyanine in Chinese Hamster Cells

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