Determination of the lifetime of singlet oxygen in water-d2 using 9,10-anthracenedipropionic acid, a water-soluble probe

Lindig, Barbara A.; Rodgers, Michael A. J.; Schaap, A. Paul

doi:10.1021/ja00537a030

Cited by 308 publications

(273 citation statements)

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“…As shown in Figs. 1(A) and 1(B), the kinetics exhibit shoulders at short irradiation times and the rate of cell inactivation is increased when the buffer is prepared in D z O or decreased when cells are previously mixed with 80 μM ADPA which is an efficient 1 O 2 quencher [31]. These results confirm that the phototoxic effect recorded in these experiments is due in large part to 1 O 2 .…”

Section: Effect Of 1 O 2 On Hiv-1 Promoter Activation In Hela Hiv-1 Csupporting

confidence: 74%

HIV-1 promoter activation following an oxidative stress mediated by singlet oxygen

Legrand-Poels¹,

Hoebeke²,

Vaira³

et al. 1993

Journal of Photochemistry and Photobiology B: Biology

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Section: Effect Of 1 O 2 On Hiv-1 Promoter Activation In Hela Hiv-1 Csupporting

confidence: 74%

HIV-1 promoter activation following an oxidative stress mediated by singlet oxygen

Legrand-Poels¹,

Hoebeke²,

Vaira³

et al. 1993

Journal of Photochemistry and Photobiology B: Biology

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“…Thus, to evaluate the ability for the two-photon sensitization of singlet oxygen in water, we employed a chemical method based on the oxidation of disodium salt of 9,10-anthracenedipropionic acid (ADPA). 16 In this approach, photobleaching of the ADPA absorbance was used to monitor singlet oxygen generation. 4c, 10 Figure 9 shows the bleaching of ADPA in water in the presence of nanoparticles coencapsulating HPPH (1.1 wt%) and BDSA (20 wt%), under two-photon irradiation at 850 nm, where ADPA has no linear absorption.…”

Section: Resultsmentioning

confidence: 99%

Organically Modified Silica Nanoparticles Co-encapsulating Photosensitizing Drug and Aggregation-Enhanced Two-Photon Absorbing Fluorescent Dye Aggregates for Two-Photon Photodynamic Therapy

et al. 2007

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We report energy-transferring organically modified silica nanoparticles for two-photon photodynamic therapy. These nanoparticles co-encapsulate two-photon fluorescent dye nanoaggregates as an energy up-converting donor and a photosensitizing PDT drug as an acceptor. They combine two features: i) aggregation-enhanced two-photon absorption and emission properties of a novel two-photon dye, and ii) nanoscopic fluorescence resonance energy transfer between this nanoaggregate and a photosensitizer, 2-devinyl-2-(1-hexyloxyethyl)pyropheophorbide. Stable aqueous dispersions of the co-encapsulating nanoparticles (diameter≤30 nm) have been prepared in the nonpolar interior of micelles by co-precipitating an organically modified silica sol with the photosensitizer and an excess amount of the two-photon dye which forms fluorescent aggregates by phase separation from the particle matrix. Using a multidisciplinary nanophotonic approach, we show: i) indirect excitation of the photosensitizer through efficient two-photon excited intraparticle energy transfer from the dye aggregates in the intracellular environment of tumor cells, and ii) generation of singlet oxygen and in-vitro cytotoxic effect in tumor cells by photosensitization under two-photon irradiation.

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“…[14] When excited at around 374 nm, the fluorescence emission of ADPA displays two strong bands centering around 400 nm and 420 nm, respectively. In the presence of singlet oxygen, ADPA is bleached to its non-fluorescent endoperoxide.…”

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confidence: 99%

Versatile Photosensitizers for Photodynamic Therapy at Infrared Excitation

et al. 2007

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A new type of photosensitizers used in photodynamic therapy, which is based on photon upconverting nanoparticles, is reported. These photosensitizers are excitable with infrared irradiation, which has several times larger tissue penetration depth than the currently available ones. They are brought close to the target cancer cells through antigen-antibody interaction with good specificity and versatility. The design is also flexible in that various photosensitive molecules can be potentially adopted into the design. Results from in vitro experiments demonstrate their promise of becoming the next generation photodynamic therapy drugs.Photodynamic therapy (PDT) is gaining acceptance as a technique for cancer treatment in recent years. [1][2][3] PDT utilizes a photosensitizer, working as a light-sensitive drug, to treat the target tissue locally upon the irradiation of light with appropriate wavelengths. It is generally accepted that the mechanism of PDT is based on the interaction between the excited photosensitizer and surrounding molecules, generating reactive oxygen species (ROS), such as singlet oxygen. ROS can cause oxidative damage to biological substrates and ultimately cell death. One of the key components in effective and efficient PDT is the photosensitizers, also called PDT drugs. Features most desired for an ideal PDT drug include: 1) Be specific to the target tissue; 2) Have a high photochemical reactivity, i.e., can effectively produce ROS when exposed to appropriate irradiation; 3) Exhibit little toxicity in the dark; and 4) Can be excited at a wavelength in the region where tissue penetration of irradiation is at a maximum. Here we report the design of a type of versatile photosensitizers, which could potentially satisfy all the above requirements and become the next generation PDT drugs, based on photon upconverting nanoparticles (PUNPs).Photon upconverting materials convert lower-energy light to higher-energy light through excitation with multiple photons. They have been widely used for some time in such applications as display, bioassay, and bioimaging, to name a few. [4] In this application, we take advantage of the fact that such materials would adsorb infrared irradiation and emit visible light to further excite the photosensitizing molecules. The particles of nanometer size would also facilitate the delivery and excretion of the proposed photosensitizer as PDT drug.The optimal spectral window for biological tissue penetration of irradiation is around 800 nm to 1 μm. Yet, single photons with infrared wavelengths are usually energetically too low for singlet oxygen generation. Multiphoton excitation using infrared light as irradiation source has been proposed and explored. [5][6][7][8][9] The new design of versatile PDT photosensitizers we propose is schematically shown in Figure 1. PUNPs are first coated with a porous, thin layer of silica. During the coating process, photosensitizing molecules with high absorbance in the spectral window matching the emission of the PUNPs are doped, ...

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Determination of the lifetime of singlet oxygen in water-d2 using 9,10-anthracenedipropionic acid, a water-soluble probe

Cited by 308 publications

References 0 publications

HIV-1 promoter activation following an oxidative stress mediated by singlet oxygen

HIV-1 promoter activation following an oxidative stress mediated by singlet oxygen

Organically Modified Silica Nanoparticles Co-encapsulating Photosensitizing Drug and Aggregation-Enhanced Two-Photon Absorbing Fluorescent Dye Aggregates for Two-Photon Photodynamic Therapy

Versatile Photosensitizers for Photodynamic Therapy at Infrared Excitation

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