Laser detection of the interaction of a sensitizer in the triplet state with oxygen in biosystems

Losev, A. P.; Knyukshto, V. N.; Zhuravkin, Ivan N.

doi:10.1007/bf02606080

Cited by 4 publications

(4 citation statements)

References 4 publications

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“…Об относительном изменении количества кислорода в ткани можно судить по тушению кислородом люминесценции ФС, возникающей в результате излучательной релаксации их T 1 -состояний [19][20][21][22][23]. Можно наблюдать как фосфоресценцию:…”

Section: Introductionunclassified

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Мониторинг Изменения Содержания Кислорода В Тканях По Кинетике Замедленной Флуоресценции Экзогенных Красителей

Летута¹,

Пашкевич²,

Алиджанов³

et al. 2019

Журнал Технической Физики

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The dynamics of oxygen consumption during photodynamic processes and its subsequent restoration in malignant tumors and healthy tissues of mice were studied in vitro by kinetics of long-term luminescence of xanthene dyes. It was shown that to estimate changes in tissue oxygen tension, specific type of delayed fluorescence can be used which caused by singlet-triplet annihilation of singlet oxygen and a sensitizer in triplet state. In tumors under pulse excitation of sensitizers, reversible quenching of delayed fluorescence was observed, which is associated with a decrease in the tissue oxygen tension during photodynamic processes. Method for visualizing the restoration of the initial oxygen level in tissues after photodynamic action is proposed.

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Section: Introductionunclassified

“…Однако в биологических системах подвижность молекул красителей ограничена [21,22], и вкладом процесса T 1 + T 1 в наблюдаемую ЗФ можно пренебречь.…”

Section: Introductionunclassified

Мониторинг Изменения Содержания Кислорода В Тканях По Кинетике Замедленной Флуоресценции Экзогенных Красителей

Летута¹,

Пашкевич²,

Алиджанов³

et al. 2019

Журнал Технической Физики

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“…Chiorophyl derivatives are very potent photosensitizers for photodynamic therapy (PDT) of tumors [1][2][3]. Their advantages as PDT photosensitizers include high molar extinction in maximum of red absorption band which is situated in the range of increased optical transparency of tissues.…”

Section: Introductionmentioning

confidence: 99%

<title>Bioelectric response of single neuron to photodynamic action of chlorin e6</title>

et al. 1996

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Photodynamic effect of chiorin e6 on bioelectric activity of single crayfish stretch receptor neuron was studied. The stable background firing of this cell provides precise evaluation of initial membrane activity shifts, dynamics of bioelectric changes, and terminal events leading to the cell death. Spikes of isolated neuron were amplified, and their frequency was continuously recorded. After 1 hour of stable control work neurons were incubated 30 mm in saline with various chiorin e6 concentrations from 30 to 500 nM, and then irradiated by helium-neon laser (632.8 nm, 0.3 W/cm). Irradiation increased firing frequency and then induced abrupt irreversible cessation of spike generation. Rate of firing acceleration and neuron lifetime quadratically depended on the dye concentration, hence the excitation of two dye molecules is need for neuron response. These data show that bioelectric activity of single nerve cell is very sensitive to chlorin e6 photodynamic injury and that plasma membrane is the main target ofphotodynamic effect.

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“…Direct observation of triplet states quenching of photosensitizer by oxygen in solutions, cells and tumor tissues is the best proof of participation of the sensitizer triplets and singlet oxygen in PDT [1][2][3]. Direct observation of triplet states quenching of photosensitizer by oxygen in solutions, cells and tumor tissues is the best proof of participation of the sensitizer triplets and singlet oxygen in PDT [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

<title>Energetics of chlorins: a potent photosensitizer of PDT</title>

Losev¹,

Nichiporovich²,

Zhuravkin

et al. 1996

SPIE Proceedings

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Number of derivatives of chiorin e6 ( mono, di and trimethyl ethers) and purpurin-18 ( monomethyl ether) potential sensitizers ofPDT have been prepared and spectral-kinetic properties their lowest electronic singlet and triplet states have been studied. The extinction of Q-band of studied chiorins much higher then convenient porphyrin photosensitizers and varies between 3 -6 . iO M' cm' . The highest degree of polarization is 0,45 and related to S1-S0 transition. Quantum yields of fluorescence p purpurin-18 in diethyl ether is lowest among of other studied chiorins and consists of 0, 10 and decreases with increasing concentration as result of the aggregation. The chiorin e6 derivatives have close values of quantum yields of fluorescence (0.16 -0, 18). Appreciable quantum yield of fluorescence is promising for application of chiorins for tumor detection due to photosensitizer retention in tumor tissues. The quantum yield of

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Laser detection of the interaction of a sensitizer in the triplet state with oxygen in biosystems

Cited by 4 publications

References 4 publications

Мониторинг Изменения Содержания Кислорода В Тканях По Кинетике Замедленной Флуоресценции Экзогенных Красителей

Мониторинг Изменения Содержания Кислорода В Тканях По Кинетике Замедленной Флуоресценции Экзогенных Красителей

<title>Bioelectric response of single neuron to photodynamic action of chlorin e6</title>

<title>Energetics of chlorins: a potent photosensitizer of PDT</title>

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