&lt;title&gt;Absorption spectroscopy as a tool to control blood oxygen saturation during photodynamic therapy&lt;/title&gt;

Stratonnikov, Alexander A.; Douplik, Alexandre; Klimov, Denis; Loschenov, Victor B.; Meerovich, Gennadii A.; Mizin, S. V.; Fomina, Galina I.; Kazachkina, Natalia I.; Yakubovskaya, Raisa I.; Budenok, Yu. V.

doi:10.1117/12.297831

Cited by 14 publications

(4 citation statements)

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“…The investigations of absorption and fluorescence spectra of Bchl-Ser, as well as the level of blood oxygenation in tumor vessels, were carried out using spectra-analyzer "LESA-01-Biospec" ("Biospec", Russia) 7,8 . The semiconductor laser (775 nm) and He-Ne laser (633 nm) were used as a light source for investigations of fluorescence.…”

Section: Methodsmentioning

confidence: 99%

<title>Fluorescent and photodynamic properties of near-infrared photosensitizer bacteriochlorophyllide-serine</title>

Меерович¹,

Kubasova²,

Оборотова³

et al. 2005

SPIE Proceedings

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Study is devoted to investigation of fluorescent and photodynamic properties of near-infrared photosensitizer bacteriochloriphyllide-serine. The peculiarities of its fluorescence excited by different lasers, dynamics and selectivity of accumulation were investigated. Photodynamic therapy of mice and investigation of tissue de-oxygenation during tumor irradiation were performed. It was shown that bacteriochloriphyllide-serine is an effective photosensitizer for PDT and fluorescent diagnostics of tumors.

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Section: Methodsmentioning

confidence: 99%

<title>Fluorescent and photodynamic properties of near-infrared photosensitizer bacteriochlorophyllide-serine</title>

Меерович¹,

Kubasova²,

Оборотова³

et al. 2005

SPIE Proceedings

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“…12,13 In living tissue, the blood oxygen level is a balance between arterial input and venous output, which are the parts of blood microcirculation supply system of tissue metabolism. 14 The photodynamic process causes damages microvasculature 15,16 and causes additional consumption of oxygen in the tissue and directly in the blood, thus shifting this balance. The decrease of blood oxygen saturation following PDT depends on irradiation photon density, photosensitizer type, its concentration in blood and surrounding tissue, and extent of blood microcirculation within the volume of light irradiation.…”

Section: Introductionmentioning

confidence: 99%

Study of photodynamic reactions in human blood

Douplik¹,

Stratonnikov

Loschenov³

et al. 2000

J. Biomed. Opt.

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Comparative studies of oxygen consumption, changes of photosensitizer fluorescence, and photodestruction of erythrocytes, and photodestruction of oxygen transport protein hemoglobin were performed during photodynamic reaction in whole and hemolyzed blood with phthalocyanines, chlorines, porphyrins, and methylene blue photosensitizers in vitro and in selected cases in vivo. The present work deals with the investigation of blood oxygen saturation SO2 and photosensitizer fluorescence during and immediately after light irradiation in the photodynamic therapy process. It has been observed that SO2 behavior strongly correlates with the type of photosensitizer. The decrease of photosensitizer fluorescence (photobleaching) during light irradiation can be followed by the recovery of the photosensitizer fluorescence immediately after interruption of the irradiation within 6-8 min. The levels of photodestruction of erythrocytes in whole blood and photodestruction of hemoglobin in hemolyzed blood in combination with the above photosensitizers reveal the influence of photodynamic reactions upon the ability of blood to transport oxygen. Maximal photohemolysis activity has been found with chlorine p6 photosensitizers.

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Section: Introductionmentioning

confidence: 99%

“…It is considered that destroying effect is mainly due to the formation of singlet oxygen resulting from the interaction of light excited photosensitizer with molecular oxygen (triplet state in the ground state). So the destroying effect will be proportional to the rate of singlet oxygen formation which is in turn depends on light intensity, photosensitizer concentration and molecular oxygen concentration [1].Proper intensity of laser could determined by the measurement of propagation of light within normal and cancer tissues. For the effective PDT, we should controlled the value of photosensitizer, power density of laser and supplied oxygen to tissue.…”

mentioning

confidence: 99%

The light propagation in biological tissue for cancer treatment

Lim

Lee²,

Kim³

et al.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Abstract-This paper is to study the accessible depth by photons within biological tissue for Photodynamic Therapy of cancer. For the measurements of light propagation within tissue, we applied the diode Laser of 660nm wavelength and by assuming the medium to be homogeneous, we neglect the effects of any refractive index mismatches between the tissue layers. The result have yielded the penetration depth of light within biological tissue. Keywords -Photodynamic Therapy, Light Propagation, Diode Laser. I. INTRODUCTIONPhotodynamic therapy is an effective method to treat cancer by means of light action on photosensitizer in tissue. It is considered that destroying effect is mainly due to the formation of singlet oxygen resulting from the interaction of light excited photosensitizer with molecular oxygen (triplet state in the ground state). So the destroying effect will be proportional to the rate of singlet oxygen formation which is in turn depends on light intensity, photosensitizer concentration and molecular oxygen concentration [1].Proper intensity of laser could determined by the measurement of propagation of light within normal and cancer tissues. For the effective PDT, we should controlled the value of photosensitizer, power density of laser and supplied oxygen to tissue. Increasing the power density of laser has problem like heating damage of tissues from laser [2,3]. High intensity of laser leads interaciton of light excited photosensitizer with molecular oxygen activity. It makes the blood oxygen saturation decrease. The interaction is also decreased due to insufficient oxygen. Stopping of irradiation increase the interaction means that pulse type of irradiation is effective method for the PDT.We measure the light propagation within biological tissue as post steps of determine the property condition of PDT like as intensity of laser power and irradiation time control.II. METHODOLOGY 1. Experimental diode Laser System Diode laser resonator, 660nm wavelength and 300mW maximum power, was used in this measurement. Diode laser system was consist of CPU, Key Input, LCD Display, Laser Resonator. Laser Power Supply and Laser Power controller. Fig.1. shows the block diagram of diode laser system. Irradiation time and frequency were changed from 10m second to 99 second on/off time by setting for variable measurement conditions. Power density was also changed 10mW/cm 2 ~ 300mW/cm 2 by controller. Measurement of light propagationThe characterstic of light within tissue is summarized reflection, absorption, scattering and penetration [4,5,6]. We measured scattering and penetration depth within biological tissue by spectroscopy. Fig. 2. shows measurement method. Light through the sample tissue was detected by spectrometer. Fig. 2. Method of measurement of light propagationWe investigated the heating damage of tissue with microscope after exposed by continuous wave form. 200mW/cm2 of power density was free from heating damage. This power was fixed to peak power of pulse waveform. We measured power density through variable...

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<title>Absorption spectroscopy as a tool to control blood oxygen saturation during photodynamic therapy</title>

Cited by 14 publications

References 0 publications

<title>Fluorescent and photodynamic properties of near-infrared photosensitizer bacteriochlorophyllide-serine</title>

<title>Fluorescent and photodynamic properties of near-infrared photosensitizer bacteriochlorophyllide-serine</title>

Study of photodynamic reactions in human blood

The light propagation in biological tissue for cancer treatment

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