Photodynamic action of LED-activated pyropheophorbide-<i>α</i>methyl ester in cisplatinresistant human ovarian carcinoma cells

Tan, Yi; Xu, Chi; Xia, Xinshu; Yu, Hongsong; Bai, Dingqun; He, Yong; Leung, Albert Wing Nang

doi:10.1002/lapl.200810139

Cited by 33 publications

(31 citation statements)

References 21 publications

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“…After the experimental conditions, as reported above, the culture medium was removed and the viable cells that remained adhered to the glass substrate were fixed in 1 mL of buffered 2.5% glutaraldehyde for 24 hours and post-fixed with 1% osmium tetroxide for 1 hour. The cells adhered to the glass substrate were then dehydrated in a series of increasing ethanol concentrations (30,50,70,95, and 100%) and immersed in 1,1,1,3,3,3-hexamethyldisilazane (HMDS; Acros Organics, Springfield, NJ, USA) for 90 min, as described elsewhere (C.A. de Souza Costa et al, 2008) and stored in a desiccator for 24 h. The cover glasses were then mounted on metallic stubs, sputter-coated with gold and the morphology of the surface-adhered L929 and MDPC-23 cells was examined with a scanning electron microscope (JEOL-JMS-T33A Scanning Microscope, Tokyo, Japan).…”

Section: Analysis Of Cell Morphology By Scanning Electron Microscopy mentioning

confidence: 99%

Nutritional stress enhances cell viability of odontoblastlike cells subjected to low level laser irradiation

Tagliani¹,

Oliveira²,

Lins³

et al. 2010

Laser Phys. Lett.

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In spite of knowing that cells under stress are biostimulated by low level laser (LLL) irradiation, the ideal condition of stress to different cell lines has not yet been established. Consequently, the aim of the present in vitro study was to evaluate the effects of a defined parameter of LLL irradiation applied on stressed odontoblast-like pulp cells (MDPC-23). The cells were seeded (12500 cells/cm 2 ) in wells of 24-well plates using complete culture medium (DMEM) and incubated for 24 hours. Then, the DMEM was replaced by a new medium with low concentrations (nutritional stress condition) of fetal bovine serum (FBS) giving rise to the following experimental groups: G1: 2% FBS; G2: 5% FBS; and G3: 10% FBS. The cells were irradiated three times with LLL in specific parameters (808±3 nm, 100 mW, 1.5 J/cm 2 ) every 24 hours. No irradiation was carried out in groups G4 (2% FBS-Control), G5 (5% FBS-Control), and G6 (10% FBS-Control). For all groups, the cell metabolism (MTT assay) and morphology (SEM) was evaluated. The experimental groups showed enhanced cell metabolism and normal cell morphology regardless of FBS concentration. A slight increase in the cell metabolism was observed only in group G2. It was concluded that cell nutritional stress caused by reducing the concentration of FBS to 5% is the most suitable method to assess the biostimulation of LLL irradiated MDPC-23 cells.MDPC-23 cells adhered to the glass substrate exhibited a spindle-shaped morphology and some mitosis were observed (arrows); SEM ×500

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Section: Analysis Of Cell Morphology By Scanning Electron Microscopy mentioning

confidence: 99%

Nutritional stress enhances cell viability of odontoblastlike cells subjected to low level laser irradiation

Tagliani¹,

Oliveira²,

Lins³

et al. 2010

Laser Phys. Lett.

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“…The recently developed light emitting diode (LED) has many advantages, for examples, inexpensive, small volume, longer life and adjustable light intensity [3,12,13]. Emerging evidences have showed that LED is a suitable light source for the management of tumors [11].…”

Section: Discussionmentioning

confidence: 99%

“…To overcome the drawbacks of the current light sources, we have set up a new light source from light emitting diode (LED) in our laboratory. Our previous study showed that [3,10,11]. The objective of this study was to investigate that LEDactivated Pa induced the cellular destruction of colon cancer cells in vitro so as to provide a foundation for in vivo study and its clinical application in the management of colon cancer.…”

Section: Introductionmentioning

confidence: 99%

“…Several studies have indicated that Pa-mediated PDT has become a promising approach for deactivating liver cancer cells [7][8][9]. However, the light sources used currently in PDT mainly are quartz-tungsten-halogen bulbs and laser [3]. To overcome the drawbacks of the current light sources, we have set up a new light source from light emitting diode (LED) in our laboratory.…”

Section: Introductionmentioning

confidence: 99%

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LED-activated pheophorbide a induces cellular destruction of colon cancer cells

Leung

Liu

et al. 2010

Laser Phys. Lett.

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Pheophorbide a (Pa) from Chinese herbal medicine Scutellaria Barbata and Silkworm Excreta shows an important promise in the photodynamic therapy on malignant tumor. The present study investigated that LED-activated Pa induced the cellular destruction of colon cancer HT-29 cells. The results showed that Pa resulted in a drug-dose dependent photocytotoxicity in the HT-29 cells, meaning the photocytotoxicity of Pa depends on the drug concentration (0 -2 μM). We further investigated the apoptosis of the HT-29 cells 18 hours after photosensitization of Pa using a confocal laser scanning microscopy with Hoechst 33258 staining. These data demonstrated that LED-activated Pa could significantly induce the cellular destruction of the HT-29 cells.The nuclear features in the HT-29 cells 18 hours after PDT with Pa (0.5 μM, 1 J/cm 2 ) observed using CLSM with Hoechst 33258 staining. PDT with Pa

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“…PPME seems, however, to be more effective at killing cisplatin-resistant ovarian cells, with which 16.71% of apoptosis has been reached. 41 …”

Section: Discussionmentioning

confidence: 99%

Optimizing photodynamic therapy by liposomal formulation of the photosensitizer pyropheophorbide-a methyl ester: In vitro and ex vivo comparative biophysical investigations in a colon carcinoma cell line

Guelluy

Fontaine‐Aupart

Grammenos

et al. 2010

Photochem Photobiol Sci

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Photodynamic therapy (PDT), induced by a photosensitizer (PS) encapsulated in a nanostructure, has emerged as an appropriate treatment to cure a multitude of oncological and non-oncological diseases. Pyropheophorbide-a methyl ester (PPME) is a second-generation PS tested in PDT, and is a potential candidate for future clinical applications. The present study, carried out in a human colon carcinoma cell line (HCT-116), evaluates the improvement resulting from a liposomal formulation of PPME versus free-PPME. Absorption and fluorescence spectroscopies, fluorescence lifetime measurements, subcellular imaging and co-localization analysis have been performed in order to analyze the properties of PPME for each delivery mode. The benefit of drug encapsulation in DMPC-liposomes is clear from our experiments, with a 5-fold higher intracellular drug delivery than that observed with free-PPME at similar concentrations. The reactive oxygen species (ROSs) produced after PPME-mediated photosensitization have been identified and quantified by using electron spin resonance spectroscopy. Our results demonstrate that PPME-PDT-mediated ROSs are composed of singlet oxygen and a hydroxyl radical. The small amounts of PPME inside mitochondria, as revealed by fluorescence colocalization analysis, could maybe explain the very low apoptotic cell death measured in HCT-116 cells.

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Photodynamic action of LED-activated pyropheophorbide-αmethyl ester in cisplatinresistant human ovarian carcinoma cells

Cited by 33 publications

References 21 publications

Nutritional stress enhances cell viability of odontoblastlike cells subjected to low level laser irradiation

Nutritional stress enhances cell viability of odontoblastlike cells subjected to low level laser irradiation

LED-activated pheophorbide a induces cellular destruction of colon cancer cells

Optimizing photodynamic therapy by liposomal formulation of the photosensitizer pyropheophorbide-a methyl ester: In vitro and ex vivo comparative biophysical investigations in a colon carcinoma cell line

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