ESR Spectroscopy of Singlet Oxygen Generated by Protoporphyrin IX in Aqueous Surfactant Solutions.

Tokuoka, Yoshikazu; Niitsu, Akane; Watabe, Naoki; Murakami, Takuro; Kawashima, Norimichi

doi:10.5650/jos.52.135

Cited by 9 publications

(8 citation statements)

References 11 publications

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“…Alternatively, it may be used exogenously and recent results show that it exhibits significant selectivity between tumor tissue and normal tissue in vivo (30). However, PpIX is hydrophobic and there are few reports of its stable formulation for systemic administration (31)(32)(33) glycol)-b-poly(caprolactone)] diblock copolymers and to measure the resulting uptake and intracellular distribution and the PDT effectiveness in RIF-1 tumor cells in vitro for this micellar formulation compared with free PpIX. The photophysical and photochemical properties of the polymeric PpIX micelles were also characterized.…”

Section: Introductionmentioning

confidence: 99%

Diblock Copolymer Micelles Deliver Hydrophobic Protoporphyrin IX for Photodynamic Therapy

Moriyama

et al. 2007

Photochem & Photobiology

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Polymeric micelles are emerging as an effective drug delivery system for hydrophobic photosensitizers in photodynamic therapy (PDT). The objective of this study was to investigate the formulation of hydrophobic protoporphyrin IX (PpIX) with MePEG(5000)-b-PCL(4100) [methoxy poly (ethylene glycol)-b-poly (caprolactone)] diblock copolymers and to compare their PDT response to that of free PpIX. The photophysical and photochemical properties of the polymeric PpIX micelles were studied by measuring absorbance and fluorescence spectra, PpIX-loading efficiency and stability, the micelle particle size and morphology, as well as singlet oxygen luminescence and lifetime. The spherical micelles have a high PpIX-loading efficiency of 82.4% and a narrow size distribution with a mean diameter of 52.2 +/- 6.4 nm. The cellular uptake of PpIX in RIF-1 cells using PpIX micelles was approximately two-fold higher than that for free PpIX. Free PpIX and PpIX formulated in micelles exhibited similar subcellular localization in or around the cellular plasma membrane, as demonstrated using fluorescence microscopy. In vitro PDT results showed that the PpIX micelles have markedly increased photocytotoxicity over that with free PpIX, by nearly an order of magnitude at the highest light dose used. The micelles alone had no evident phototoxicity or dark toxicity. These findings suggest that MePEG(5000)-b-PCL(4100) diblock copolymer micelles have great potential as a drug delivery system for hydrophobic photodynamic sensitizers.

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Section: Introductionmentioning

confidence: 99%

Diblock Copolymer Micelles Deliver Hydrophobic Protoporphyrin IX for Photodynamic Therapy

Moriyama

et al. 2007

Photochem & Photobiology

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“…expresses the relative intensity of the ESR signal of the TMPD nitroxide radical against that of the manganese markers on the both sides of the ESR spectra shown in . The relative intensity corresponds to a quantity of singlet oxygen generated 15) . The relative intensity shown in rises with irradiation time and becomes almost constant over 10-min light irradiation.…”

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confidence: 99%

Oxidation Decomposition of Unsaturated Fatty Acids by Singlet Oxygen in Phospholipid Bilayer Membranes

et al. 2007

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Oxidation decomposition of unsaturated fatty acids with singlet oxygen generated from a photosensitizing agent was investigated in liposome bilayer membranes under a light irradiation condition. The liposome of which the bilayer membrane was composed of L-alpha-dipalmitoylphosphatidylcholine (DPPC), protoporphyrin IX (PpIX), and an unsaturated fatty acid (oleic acid, linoleic acid, alpha-linolenic acid, or arachidonic acid) were prepared with Bangham's method. In irradiating the liposome dispersion with light ranged from 550 to 750 nm, the unsaturated fatty acid was decomposed through an oxidation reaction with singlet oxygen. The decomposition rate constant was obeyed as the following order: arachidonic acid > oleic acid > alpha-linolenic acid > linoleic acid. This result indicates that oleic acid is readily degraded despite its lower unsaturated degree. In addition, micropolarity and microfluidity of the hydrocarbon region in the liposome bilayer membrane including the unsaturated fatty acid and PpIX decreased with an increase in light irradiation time. These findings suggest that interaction among the hydrocarbon chains of DPPC in the liposome bilayer membrane is promoted by migration of the oxidized unsaturated fatty acid from the hydrocarbon region, leading to form close-packed and well-ordered orientation of the hydrocarbon chains.

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“…Three equivalent-height peaks between Mn markers indicated oxidization of TMPD by 1 O 2 . As TMPD is able to selectively trap 1 O 2 [17], 1 O 2 production can be assessed based on the peak area of oxidized TMPD. Figure 4 shows the correlation between BL irradiation time and 1 O 2 production, as measured by TMPD peak area.…”

Section: Esr Measurementsmentioning

confidence: 99%

“…In the present study, we investigated whether some photo-excited carotenoids have photosensitizing ability and whether they are able to produce ROS. We also examined 1 O 2 production using an ESR spin trapping technique with a singlet oxygen trapping agent, 2,2,6,6-tetramethil-4-piperidone (TMPD) (Nacalai Tesque, Kyoto, Japan) [17].…”

Section: Introductionmentioning

confidence: 99%

Photo-excitation of carotenoids causes cytotoxicity via singlet oxygen production

Yoshii

Asai

et al. 2012

Biochemical and Biophysical Research Communications

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Carotenoids, natural pigments widely distributed in algae and plants, have a conjugated double bond system. Their excitation energies are correlated with conjugation length. We hypothesized that carotenoids whose energy states are above the singlet excited state of oxygen (singlet oxygen) would possess photosensitizing properties. Here, we demonstrated that human skin melanoma (A375) cells are damaged through the photo-excitation of several carotenoids (neoxanthin, fucoxanthin and siphonaxanthin). In contrast, photo-excitation of carotenoids that possess energy states below that of singlet oxygen, such as β-carotene, lutein, loroxanthin and violaxanthin, did not enhance cell death. Production of reactive oxygen species (ROS) by photo-excited fucoxanthin or neoxanthin was confirmed using a reporter assay for ROS production with HeLa Hyper cells, which express a fluorescent indicator protein for intracellular ROS. Fucoxanthin and neoxanthin also showed high cellular penetration and retention. Electron spin resonance spectra using 2,2,6,6-tetramethil-4-piperidone as a singlet oxygen trapping agent demonstrated that singlet oxygen was produced via energy transfer from photo-excited fucoxanthin to oxygen molecules. These results suggest that carotenoids such as fucoxanthin, which are capable of singlet oxygen production through photo-excitation and show good penetration and retention in target cells, are useful as photosensitizers in photodynamic therapy for skin disease.

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ESR Spectroscopy of Singlet Oxygen Generated by Protoporphyrin IX in Aqueous Surfactant Solutions.

Cited by 9 publications

References 11 publications

Diblock Copolymer Micelles Deliver Hydrophobic Protoporphyrin IX for Photodynamic Therapy

Diblock Copolymer Micelles Deliver Hydrophobic Protoporphyrin IX for Photodynamic Therapy

Oxidation Decomposition of Unsaturated Fatty Acids by Singlet Oxygen in Phospholipid Bilayer Membranes

Photo-excitation of carotenoids causes cytotoxicity via singlet oxygen production

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