Characterisation of the photochemotherapeutic agent disulphonated aluminium phthalocyanine and its high-performance liquid chromatographic separated components

Bishop, Steven M.; Khoo, Bee J.; MacRobert, AJ; Simpson, Mary S. C.; Phillips, David; Beeby, Andrew

doi:10.1016/0021-9673(93)83347-u

Cited by 35 publications

(14 citation statements)

References 15 publications

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“…Disulfonated aluminium phthalocyanine was prepared according to the method of Ambroz et al 11,12,23 The AlPcS 2 synthesised by this procedure are the so-called cis-isomers (structures 1 and 2). These isomers are inseparable, and are present in the ratio 2 : 1.…”

Section: Sensitisermentioning

confidence: 99%

Fluorescence lifetime measurements of disulfonated aluminium phthalocyanine in the presence of microbial cells

Lacey

Phillips

2002

Photochem Photobiol Sci

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The fluorescence lifetimes of disulfonated aluminium phthalocyanine (AlPcS2) in the presence of several different microbial cells are measured using the technique of time correlated single photon counting (TCSPC) employing front-face illumination. The microbes studied are: Escherichia coli, Porphyromonas gingivalis (Gram-negative bacteria), Streptococcus mutans (a Gram-positive bacterium), and the yeast Candida albicans. Complex fluorescence decays are observed when AlPcS2 is in the presence of these microbes; the fluorescence decay data can be fitted to a distribution of exponential lifetimes indicating that the AlPcS2 molecules experience a range of micro-environments The average fluorescence lifetimes of AlPcS2 in the presence of the microbes studied range from 4.85 to 5.95 ns, indicating differences in the cellular localisation of AlPcS2 with each of the microbes studied. These novel data are presented alongside a brief summary of existing AlPcS2 fluorescence lifetime data measured both in solution and in model biological systems.

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Section: Sensitisermentioning

confidence: 99%

Fluorescence lifetime measurements of disulfonated aluminium phthalocyanine in the presence of microbial cells

Lacey

Phillips

2002

Photochem Photobiol Sci

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“…The purity of the samples was checked using reversed-phase HPLC. 22 Water was purified by distillation followed by processing in an ELGA UHQ. Methanol and ethanol (BDH, HPLC grade) were tested to ensure that no extraneous fluorescence was present and used without further purification.…”

Section: Chemicalsmentioning

confidence: 99%

Phthalocyanine Fluorescence at High Concentration: Dimers or Reabsorption Effect?

Dhami

Mello

Rumbles

et al. 1995

Photochem & Photobiology

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209

155

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For tetrasulfonated aluminum phthalocyanine (AlPcS,), dimer formation is characterized in the absorption spectrum by a broadening of the Q-band and the appearance of a new band at the red edge of the spectrum. The high concentrations required to produce dimers, however, often leads to anomalous observations in fluorescence spectroscopy. In the present study, we have examined the photophysical characteristics of two dye systems; AlPcS, in a 66% ethanovwater mixture and disulfonated aluminum phthalocyanine in methanol. Using absorption spectroscopy, the formation of dimers is shown to be prevalent only in the case of AIPcS,. The fluorescence emission spectra in both cases, however, exhibit similar spectral changes with increasing dye concentration. The measured fluorescence decay profiles for both dyes also show similar trends: They are monoexponential, invariant with emission wavelength and have decay times that increase with dye concentration. These distortions are sometimes incorrectly attributed to dimer fluorescence. We find no evidence for the existence of dimer fluorescence and demonstrate that these data can be readily explained, by taking into consideration the effects of reabsorption of fluorescence.

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“…This fraction contained a range of disulphonated isomers dominated by the most hydrophobic component, which comprised 60±5% of its integrated HPLC. 29 The photosensitiser was made up in 0 1 molar sodium hydroxide and phosphate buffered saline and given intravenously through the tail vein. ALA was obtained as a hydrochloride (formula weight = 167-6) in 98% pure powder form from Sigma Chemical Company (Poole, UK).…”

Section: Photosensitisersmentioning

confidence: 99%

Mucosal ablation using photodynamic therapy for the treatment of dysplasia: an experimental study in the normal rat stomach.

Loh

MacRobert

Buonaccorsi

et al. 1996

Gut

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Surgery is the only effective treatment for dysplasia in the gastrointestinal tract with considerable associated morbidity and mortality and is difficult to justify without confirmed malignancy. Photodynamic therapy (PDT) produces localised necrosis, which can be limited to the mucosa. This study examined the mechanical properties ofthe normal rat stomach after PDT. The aim of this study was to measure the bursting pressure of PDT lesions in the stomach and to assess gastric emptying after producing circumferential mucosal necrosis at the pylorus by PDT. Two photosensitising agents were used -5-aminolaevulinic acid (ALA), and aluminium disulphonated phthalocyanine (A1S2Pc). Normal rats were sensitised and PDT lesions created in the stomach with red light. The bursting pressure was measured and compared with that in thermal control lesions. In further experiments, circumferential mucosal necrosis was produced at the pylorus, and animals observed for subsequent eating and weight gain. It was found that gastric bursting pressure was reduced after thermal injury, but not at any time after PDT (with AlS2Pc, but not ALA, adhesive omental reinforcement was required to maintain the gastric wall strength at one week). For the pyloric lesions, gastric emptying was permanently impaired using AlS2Pc, but with low dose ALA (20 mg/kg) had returned to normal by three days. With ALA, but not AlS2Pc, necrosis could be limited to the mucosa. In conclusion, using ALA, selective ablation of the gastric mucosa is possible, which does not reduce the strength of the stomach and only temporarily delays gastric emptying. PDT is a promising technique for the circumferential ablation of dysplastic mucosa. (Gut 1996; 38: 71-78)

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Characterisation of the photochemotherapeutic agent disulphonated aluminium phthalocyanine and its high-performance liquid chromatographic separated components

Cited by 35 publications

References 15 publications

Fluorescence lifetime measurements of disulfonated aluminium phthalocyanine in the presence of microbial cells

Fluorescence lifetime measurements of disulfonated aluminium phthalocyanine in the presence of microbial cells

Phthalocyanine Fluorescence at High Concentration: Dimers or Reabsorption Effect?

Mucosal ablation using photodynamic therapy for the treatment of dysplasia: an experimental study in the normal rat stomach.

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