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Introducción: El oxígeno singulete es una especie reactiva que se obtiene mediante transferencia energética usando un fotosensibilizador. Su cuantificación directa requiere de instrumentación costosa, por lo cual es necesario recurrir a métodos indirectos que tengan suficiente selectividad y bajo costo. Estos procedimientos se basan en la interceptación química del oxígeno singulete produciendo una especie que se pueda detectar por métodos analíticos convencionales. En este artículo se describe la utilización del 9-[(E)-2-feniletenil] antraceno 1 (PEA) y del 9-[(E)-2-(naftalen-2-il) etenil]antraceno 2 (NEA), como alternativas viables y económicas para la cuantificación indirecta del oxígeno singulete, en medios acuosos. Su ventaja radica en la fácil detección de la desactivación de su fluorescencia una vez son oxidados por el oxígeno singulete. Materiales y Métodos: Los compuestos se sintetizaron y caracterizaron siguiendo procedimientos previamente reportados. Su capacidad para atrapar oxígeno singulete se determinó siguiendo su oxidación fotosensibilizada en solución de H2O/THF y en parásitos de Leishmania tarentolae, empleando azul de metileno o rosa bengala como fotosensibilizadores. Las muestras experimentales se iluminaron con una lámpara de emisión de luz visible, y se utilizaron métodos espectroscópicos (absorción UV-Vis, fluorescencia, RMN-1H) y espectrometría de masas para monitorear el atrapamiento y fotooxidación. Resultados y Discusión: Las pruebas espectroscópicas demostraron la capacidad que tienen los compuestos PEA 1 y NEA 2 para atrapar oxígeno singulete en solución acuosa y dentro de parásitos de L. tarentolae. Estudios de viabilidad parasitaria demuestran que PEA 1 es citotóxico en la oscuridad y cuando los cultivos son expuestos a la luz, mientras que NEA 2 no es citotóxico en la oscuridad, pero sí lo es cuando el cultivo es expuesto a la luz. En conclusión, los compuestos estudiados pueden servir como sondas para detectar y medir la producción de oxígeno singulete en medio acuoso y potencialmente en cultivos celulares, aunque es recomendable evaluar su actividad citotóxica en la oscuridad y bajo iluminación en estos casos.
Introduction: Singlet oxygen is a reactive species obtained via energy transfer using a photosensitizer. Its direct quantification requires expensive instrumentation, so it is necessary to use indirect methods having sufficient selectivity and low cost. These procedures are based on the chemical interception of singlet oxygen producing a species that can be detected using conventional analytical methods. This article describes the utilization of 9-[(E)-2-phenylethenyl]anthracene 1 (PEA) and 9-[(E)-2-(naphtalen-2-yl)ethenyl]anthracene 2 (NEA) as suitable and economic alternatives for the indirect quantification of singlet oxygen in aqueous media. Their advantage is the easy detection of their fluorescence once they are oxidized by singlet oxygen. Materials and Methods: Compounds were synthesized and characterized following procedures previously reported. Their capacity to trap singlet oxygen was determined by monitoring their photosensitized oxidation in either a H2O/THF solution or within Leishmania tarentolae parasites, utilizing methylene blue or rose bengal as photosensitizers. Experimental samples were illuminated with a lamp emitting visible light, while spectroscopical techniques (absorption, fluorescence, 1 H-NMR) and mass spectrometry were used to monitor trapping and photooxidation. Results and Discussion: Spectroscopical evidence demonstrates that both PEA 1 and NEA 2 are capable of trapping singlet oxygen in both aqueous media and within L. tarentolae parasites. Viability studies demonstrate that PEA 1 is cytotoxic in the dark and when parasite cultures were exposed to light, while NEA 2 does not show dark cytotoxicity, but is toxic when cultures were exposed to light. It can be concluded that both compounds under study may be utilized as probes to detect and quantify the production of singlet oxygen in aqueous media and potentially in cell cultures, although it is recommended to evaluate their cytotoxic activity both in the dark and upon light exposure in these cases.
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Objective: To study the effect of new photosensitizer Chlorophyl-derivative (CPD4) combined with Adriamycin on cell cycle and cell proliferation of MCF-7 breast cancer cell line and to investigate the mechanism of combination therapy. Methods: A new type of photosensitizer and traditional chemotherapy drug Adriamycin (ADM) were used to treat breast cancer cell line MCF-7. Flow cytometry was employed to detect apoptosis rate and cell cycle distribution in ADM group, group with photodynamic effect and the combined group. The influence of ADM on the mean fluorescence intensity and the changes in the mean fluorescence intensity after CPO4 (1.5μg/mL) treatment were analyzed. Results: The apoptosis rate of the combination group was higher than that in the other two groups, with statistical significance (P＜0.01). Photodynamic effect caused G_0/G_1 phase arrest in MCF-7 cells. Low concentration of ADM increased the number of G_2/M phase cells. The percentage of G_2/M phase cells was increased in the combination group. No significant difference was found in the mean fluorescence intensity between ADM pretreated MCF-7 cells for 24 hours and 48 hours and the control group (P＞0.05). Pretreatment of MCF-7 cells with ADM increased the volume of photosensitizer CPD4 into the cells. The mean fluorescence intensity at 2 hours after CPD4 incubation was the highest. Conclusion: ADM can increase the amount of CPD4 into the MCF-7 cells. Photodynamic therapy com-bined with Adriamycin has a synergistic effect on MCF-7 cells.
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Objective To investigate the photodynamic effect induced by laser and use it as a method for purging of minimal residual tumor cells from autologous peripheral blood stem cell grafts. Methods We studied the effect of various concentrations of hematoporphyrin derivative (HPD) combined with of different time of laser irradiation on human leukemia cell line K562, breast tumor cell line MCF-7 and human umbilical cord blood-derived hematopoietic stem/progenitor cells by using MTT assay to compare the photodynamic effect between cell lines of each group. Results HPD or laser irradiation alone had no apparent cytotoxicity while the application of HPD plus laser exposure caused photosensitization. HPD plus laser irradiation was more efficient for killing K562 cells and MCF-7 cells than doing the normal human umbilical cord blood-derived hematopoietic stem/progenitor cells. The photodynamic effect on K562 cells and MCF-7 cells was positively correlated with the increase of treatment duration and HPD concentration. Conclusion These results indicated that the laser photodynamic effect mediated by HPD might be used for purging autologous peripheral blood stem cell grafts in vitro.
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The preparation,chemical composition and physicochemical properties of photocar-cinorin (PsD-007),a new drug of photolocalizaion and photochemotherapy for human malignancies,are reported here.It has been shown by the resul s of thin layer and high performance liquid chromatographic (TLC & HPLC) analyses that about 85% of its total weight are relatively hydrophobic porphyrins of unknown structure in which a fraction with the same retention time as .hematoporphyrin(Hp)monoacetate constituts over 60%.There are also 4.2% of Hp,8.6% of 3(8) hydroxycthy lS-(3)-vinyldcutero-porphyrin (HVD) and 0.6% of portoporphyrin (Pp) in this drug.The presence and amount of HVD in PsD-007 were determined by an authentic sample prepared in our laboratory.The changes of the composition of PsD-007 on exposure to different doses of argon laser (488+ 514.5nm) were detected by HPLC.The variations in Soret peak of UV absorption spectra of PsD-007 protected from light at a constant temperature were also determined
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The results of observation on experimental photolocalization and photochemotherapy with a new drug photocarcinorin (PsD-007) and argon laser (514.5+ 488nm) for different transplanted animal tumors are reported.The interrelationship among the dose of light irradiation,dose level of the drug and the efficiency of experimental photodiagnosis and photochemotherapy for animal tumors was studied.It has been shown that the degree of photodynamic damage on tumors is proportional to the light dose.The upper and lower thresholds of effective light-dose seem to be about 150 mw/cm2 and 40 mw/cm2 for 30 min respectively.The light dose for curing half of experimental animals ranged from 80 to 100 mw/cm2 for 30 min with a drug dose of 5mg/kg.The photodynamic damage on tumors in closely correlated to drug dose with a given light dose.The photodynamic effects on different tumors are essentially consistent with each other.A bright oranged-red fluorescence appeared on the fumor tissues of S180 sarcoma,Lewis lung carcinoma or U14 cervical carcinoma bearing mice on exposure to argon laser and/or UV light (365nm) 24 and 48 h after the injection of 5mg/kg of PsD-007.But no fluorescence was found on the normal tissues around the tumors under the same conditions.It is suggested that PsD-007 may be specifically uptaken into the malignant tissues.The intensity of fluorecence on tumors is directly proportional to drug dose and inversely proportional to the time interval between drug administration and observation on the fluorescence.The homogeneity of distribution of light energy was improved by using a "lens aperture" placed between the light source and irradiated animal.A model system was thus provided for the evaluation of the efficiency of drugs in the photochemodiagnosis and photochemotherapy for animal tumors.
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Fortyfour male Kunming mice, weighing 20-25g. were used. The HpD was injected (10mg/kg) into the caudal vein of 32 mice individually. After 48 hours, the kidneys were radiated directly by the dye-laser for 10 minutes (630nm, 250-300J/cm~2). Then, the kidneys were observed at different times. 12 normal male mice served as control. The experiment demonstrated that when HpD was activated by laser, it could produce the necrotic effect on the renal tissues. The different structures of the kidney showed different susceptibility to HpD-laser. The proximal convoluted tubules and capillaries were injured earlier than the distal convoluted tubules and the collecting tubules. The first morphologic changes observed electron microscopically were the swelling of mitochondria and the formation of vesicles on the cell membrane. Finally, they were completely disrupted. The damages of lysosomes, endoplasmic reticula, ribosomes and cell nucleus followed. The activity of some enzymes in the kidney were inhibited. The sequence of the extents of the enzymes being inhibited was AkP, AcP, Cytox, SDH. The mucopolysaccharides ran off the brush border in proximal convoluted tubules. The results of this study suggested that the various susceptibilities to HpD-laser are chiefly due to the different structures and their functional conditions in the kidney. The main photodynamic effect is presented as the injury of the membrane system of the cell.