A chemical dosimeter for the determination of the photodynamic activity of photosensitizers

Fischer, F.; Graschew, Georgi; Sinn, H.; Maier‐Borst, W.; Lorenz, Walter J.; Schlag, P. M.

doi:10.1016/s0009-8981(98)00045-x

Cited by 58 publications

(50 citation statements)

References 14 publications

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“…It has been shown that oxygen plays a fundamental role in the photochemistry of many photosensitizing drugs used in photodynamic therapy. 7 The products of UA photosensitized oxygenation via 1 O 2 in human serum are known 12 to be triuret, sodium oxanate, allantoxaidin and CO 2 ( Figure 4) Figure 5.…”

Section: Uric Acid Testmentioning

confidence: 99%

Synthesis, spectroscopy and photosensitizing properties of hydroxynitrophenylporphyrins

Maestrin¹,

Tedesco²,

Neri³

et al. 2004

J. Braz. Chem. Soc.

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As hidroxinitrofenilporfirinas, 5,10,15,20-tetrakis(2-hidroxi-5-nitrofenil)porfirina e 5-mono(carboxifenil)-10,15,20-tris(2-hidroxi-5-nitrofenil)porfirina, estudadas neste trabalho, foram preparadas pelo método de Adler e caracterizadas por 1 H RMN e por espectroscopia de absorção e emissão na região espectral visível. A formação de 1 O 2 foi constatada através do teste do ácido úrico (AU), o qual consiste na observação do decréscimo na absorbância da banda do AU em 293 nm, após irradiação da solução, com laser, contendo o fotossenssibilizador e o AU. Os resultado obtidos indicaram que as hidroxinitrofenilporfirinas podem ser consideradas potenciais fotossensibilizadores para terapia fotodinâmica.The hydroxynitrophenylporphyrins, 5,10,15,20-tetrakis(2-hydroxy-5-nitrophenyl)porphyrin and 5-mono(carboxyphenyl)-10,15,20-tris(2-hydroxy-5-nitrophenyl)porphyrin described in this work were prepared through Adler's method. These compounds were characterized by 1 H NMR and light absorption and emission spectroscopy in the visible region. In order to demonstrate the involvement of 1 O 2 production, the uric (UA) acid test was carried out, which considers the decrease in the absorbance of UA at 293 nm following laser light irradiation of a solution containing UA and a photosensitizer. The results obtained demonstrate that these hydroxynitrophenylporphyrins can be considered as promising photosensitizers in PDT.

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Section: Uric Acid Testmentioning

confidence: 99%

Synthesis, spectroscopy and photosensitizing properties of hydroxynitrophenylporphyrins

Maestrin¹,

Tedesco²,

Neri³

et al. 2004

J. Braz. Chem. Soc.

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“…In order to verify the new chlorins ability to act as photosensitizers in PDT, tests with uric acid, a known singlet oxygen scavenger, were performed with chlorin 3 (5,10,15,20-tetrakis(pentafluorophenyl)-tetrahydro-1H-N-methylpyrrolo-porphyrin) (this one being used for comparison purposes) and 4, the new one formed in higher yield. 14 …”

Section: Introductionmentioning

confidence: 99%

A novel chlorin derivative of Meso-tris(pentafluorophenyl)-4-pyridylporphyrin: synthesis, photophysics and photochemical properties

Maestrin¹,

Ribeiro²,

Tedesco³

et al. 2004

J. Braz. Chem. Soc.

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A terapia fotodinâmica (TFD) está baseada na administração e no acúmulo de fotossensibilizador, por exemplo, de tipo porfirina ou clorina, em tecidos doentes. As clorinas apresentam propriedades fotofísicas semelhantes àquelas das porfirinas, mas com intensificação e deslocamento das bandas Q, o que faz com que sejam bons candidatos para TFD. Neste trabalho relata-se a síntese da 5,10,15-tris(pentafluorofenil)-20-(4-piridil)porfirina, (2), e das clorinas isômeras 4, (5,10,20-tris(pentafluorofenil)-15-(4-piridil)-tetra-hidro-1H-N-metil-pirrolo[3,4-b]porfirina e 5, (5,10,15-tris(pentafluorofenil)-20-(4-piridil)-tetra-hidro-1H-N-metil-pirrolo[3,4-b]porfirina, obtidas a partir de 2, por reação de cicloadição 1,3-dipolar com um ileto azometínico, e respectivas caracterizações estruturais por UV-Vis, RMN e EM-FAB. Foram avaliadas as propriedades fotofísicas, fotoquímicas e fotodegradativas para a nova clorina 4, obtida com melhor rendimento que o seu isômero 5. O rendimento quântico de fotodegradação (φ Fd , mol Einstein -1 ) foi de 0,047±0,014. Foram ainda realizados testes com ácido úrico para demonstrar a capacidade do fotossensibilizador na produção de 1 O 2 . Os resultados mostraram que a nova clorina 4 pode ser considerada como um bom fotossensibilizador para TFD.Photodynamic therapy (PDT) is based on the accumulation of a photosensitizer, such as a porphyrin or a chlorin, in a malignant tissue after its administration. Chlorins exhibit photophysical properties similar to those of the porphyrin macrocycles, but with intensified and red-shifted Q bands, making chlorin-containing systems even better candidates for PDT. In this contribution, we report the synthesis of 5,10,15-tris(pentafluorophenyl)-20-(4-pyridyl)porphyrin, (2) and its transformation to the novel chlorin derivatives 4, (5,10,20-tris(pentafluorophenyl)-15-(4-pyridyl)-tetrahydro-1H-N-methyl-pyrrolo [3,4-b]porphyrin and 5, (5,10,15-tris(pentafluorophenyl)-20-(4-pyridyl)-tetrahydro-1H-N-methyl-pyrrolo[3,4-b]porphyrin) by 1,3-dipolar cycloaddition with an azomethine ylide. The new products have been characterized by UV-Vis, 1 H NMR and FAB-MS. The photophysics, photochemical and photobleaching properties of chlorin 4 have been evaluated. Its quantum yield of photobleaching (φ Pb , mol Einstein -1 ) was 0.047±0.014. In order to demonstrate the production of 1 O 2 when 4 is used as a photosensitizer, uric acid tests have been carried out. The results indicate that chlorin 4 can be considered a promising photosensitizer in PDT.

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“…This involves the use of a light-activatable compound, a photosensitizer, which generates singlet oxygen and free radicals when exposed to light of a suitable wavelength (11,16,37). Singlet oxygen is highly reactive and cytotoxic, damaging and destroying cell walls and membranes and thus resulting in cell death (2,3).…”

mentioning

confidence: 99%

Development of a Novel Targeting System for Lethal Photosensitization of Antibiotic-Resistant Strains of Staphylococcus aureus

Embleton

Nair

Heywood

et al. 2005

Antimicrob Agents Chemother

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Light-activated antimicrobial agents (photosensitizers) are promising alternatives to antibiotics for the treatment of topical infections. To improve efficacy and avoid possible damage to host tissues, targeting of the photosensitizer to the infecting organism is desirable, and this has previously been achieved using antibodies and chemical modification of the agent. In this study we investigated the possibility of using a bacteriophage to deliver the photosensitizer tin(IV) chlorin e6 (SnCe6) to Staphylococcus aureus. SnCe6 was covalently linked to S. aureus bacteriophage 75, and the ability of the conjugate to kill various strains of S. aureus when exposed to red light was determined. Substantial kills of methicillin-and vancomycin-intermediate strains of S. aureus were achieved using low concentrations of the conjugate (containing 1.5 g/ml SnCe6) and low light doses (21 J/cm 2 ). Under these conditions, the viability of human epithelial cells (in the absence of bacteria) was largely unaffected. On a molar equivalent basis, the conjugate was a more effective bactericide than the unconjugated SnCe6, and killing was not growth phase dependent. The conjugate was effective against vancomycin-intermediate strains of S. aureus even after growth in vancomycin. The results of this study have demonstrated that a bacteriophage can be used to deliver a photosensitizer to a target organism, resulting in enhanced and selective killing of the organism. Such attributes are desirable in an agent to be used in the photodynamic therapy of infectious diseases.

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A chemical dosimeter for the determination of the photodynamic activity of photosensitizers

Cited by 58 publications

References 14 publications

Synthesis, spectroscopy and photosensitizing properties of hydroxynitrophenylporphyrins

Synthesis, spectroscopy and photosensitizing properties of hydroxynitrophenylporphyrins

A novel chlorin derivative of Meso-tris(pentafluorophenyl)-4-pyridylporphyrin: synthesis, photophysics and photochemical properties

Development of a Novel Targeting System for Lethal Photosensitization of Antibiotic-Resistant Strains of Staphylococcus aureus

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