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Optik - International Journal for Light and Electron Optics 01/2013; · 0.51 Impact Factor
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ABSTRACT: Drug delivery into the malignant cell is a basic requirement for effectiveness of photosensitizing systems for photodynamic
therapy (PDT). For anticancer tumoricidal drugs, e.g., 5-aminolevulinic acid (ALA), zinc oxide (ZnO) nanoparticles (NPs) are
used as efficient intracellular photosensitizer carriers. Apoptotic effect of tumoricidal drugs (ALA and Photofrin cells in
the presence and absence of ZnO NPs using confocal microscopy as well as Neutral Red Assay (NRA). In dark, ZnO NPs conjugated
with ALA or Photofrinhas been found to have a remarkable fluorescence in Hepatucellular carcinoma (HepG2) cells. This fact
illustrates the great potential of ZnO NPs as biomarker in relevant clinical and biomedical applications.
Laser Physics 04/2012; 21(12):2156-2164. · 3.61 Impact Factor
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ABSTRACT: Present study evaluates the effects of photodynamic therapy (PDT) with aminolevulinic acid (5-ALA) as photo sensitizer using
Human embryonic kidney (HEK293T) cell line as an experimental model. Porphyrins derivatives are used as active cytotoxic antitumor
agents in PDT. Above mentioned cell line were irradiated with red light (a diode laser, λ = 635 nm) at different doses (0–160
J/cm2) of light. The influence/effectiveness of incubation time, various concentrations of aminolevulinic acid (5-ALA) and light
doses on the cellular viability was studied. HEK293T cells were deliberated by exposing the ALA-PpIX (0–1000 μg/ml) of concentrations.
The optimal uptakes of photosensitizer (PS) in cell lines were investigated by means of spectro photo metric measurements.
Cells viability was determined by means of neutral red assay (NRA). It was observed that alone, neither photosensitizer nor
light dose have significant effect on cells viability, but optimal concentration of PS along with suitable dose of light exhibit
effective impact on the viability of cell. Our results showed that light doses of 40 J/cm2 demonstrates effective PDT outcome for HEK293T cell line when incubated with 400 μg/ml, with wrapping up view that HEK293T
cell line is very sensitive to ALA-mediated PDT as compared to cell line published in our data. At the end results has been
verified by using reactive oxygen species (ROS) measure test.
Laser Physics 04/2012; 21(8):1428-1437. · 3.61 Impact Factor
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ABSTRACT: The purpose of the present study is to determine the optical properties of normal and thermally coagulated chicken liver at
720, 740, 770, 810, 825 and 840 nm wavelengths of laser irradiation. So, we were able to evaluate these optical properties
(absorption and scattering coefficients) with ex-vivo study using Kubelka Munk Model (KMM) from the radial dependence of the diffuse reflectance with femtosecond pulsed laser
in near IR region. These coefficients were significantly increased with coagulation. The penetration depths of the diffused
light have been reported to a maximum value of 8.12 ± 0.36 mm in normal liver and 2.49 ± 0.17 mm in coagulated liver at 840
nm showing increasing behavior towards IR region. The Monte Carlo simulation was used to check the theoretical validation
of measured optical properties of the tissue that showed a good match with our experimental results. We believe that these
differences in optical properties will be helpful for the understanding arid optimal use of laser applications in medicine
and differential diagnosis of tissues by using different optical methods. Especially for the investigation of biological tissue
for photodynamic therapy (PDT), the knowledge of the specific optical properties and their thermo-induced changes is important.
Optics and Spectroscopy 04/2012; 110(2):313-319. · 0.61 Impact Factor
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ABSTRACT: Significant apoptotic effect in Hep2c cell line has been investigated, when diode laser (λ = 635 nm, red) are used as a source
of illumination and initiation of photodynamic action. The optimal uptake time of Photofrin® for Hep2c cell line was investigated
by means of spectrophotometric measurement. Quantification of the live cell population was determined by means of neutral
red assay (NRA). The spectrometry measurements showed that after 46 h incubation, the maximal cellular uptake of Photofrin®
was achieved and photocytotoxic assay showed that light dose of 120 J/cm2 give effective PDT outcome for Hep2c cell line incubated with 85 μg/ml of Photofrin®. No significant phototoxic and cytotoxic
effects on Hep2c cells were observed due to light doses or photosensitize, when studied independently of each other and Photofrin®
showed good anti tumor effects.
Laser Physics 04/2012; 21(7):1235-1242. · 3.61 Impact Factor
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ABSTRACT: We report a two dimensional Stokes vector imaging technique for transamination measurements of the polarization state of scattering
medium. Measurement of the depth resolved Stokes parameters allows determination of the degree of polarization, birefringence,
retardation, optical activity and characterization of the medium. The polarized light preserved and degree of polarization
very with scatterer concentration. The transmitted intensity patterns by varying a polarization state of the incident laser
light (λ = 632.8 nm) and changing analyzer configuration provides a useful information about concentration, orientation, and
shape of the sample under investigation. The results are important for the understanding of polarization phenomenon in turbid
media, like biological tissues.
Optics and Spectroscopy 04/2012; 110(3):438-441. · 0.61 Impact Factor
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DOI : 10.1109/ICoBE.2012.6179012 IEEE, 237-241; 02/2012
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Laser Physics 01/2012; · 3.61 Impact Factor
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Laser Physics 01/2012; · 3.61 Impact Factor
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Lasers in Engineering 01/2012; · 0.16 Impact Factor
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Photodiagnosis & Photodynamic Therapy. 01/2011; 8:145-146.
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Laser Physics 01/2011; 21:2156-2164. · 3.61 Impact Factor
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Laser Physics 01/2011; 21:427-433. · 3.61 Impact Factor
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Optics and Spectroscopy. 01/2011; 110(2):313–319.
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Optics and Spectroscopy. 01/2011; 110:311-317.
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ABSTRACT: Experiments were carried out on cancerous HeLa cells and blood serum using a double integrating sphere and a He-Ne laser to investigate the optical properties and cellular effects due to photodynamic therapy (PDT). In the first experiment, HeLa cells were exposed to Photofrin at concentrations of 0, 10, 20, 30, 50 and 112.4 microg/ml at an irradiance of 0.2 W/cm(2) using diode laser light. Using a confocal microscope, cell debris and morphological changes in HeLa cells were recorded at different Photofrin concentrations. The results showed cell debris in HeLa cells at the highest concentration of Photofrin. In a second experiment, photobleaching was observed in HeLa cells in the presence of various concentrations of 5-aminolaevulinic acid ranging from 0-50 microg/ml. There was progressive degradation of the 635 nm peak during continuous laser irradiation at an irradiance of 0.2 W/cm(2). We conclude that cells demonstrating high initial fluorescence undergo bleaching at a faster rate than those with lower fluorescence. Finally in a third experiment, cancerous and noncancerous blood serum was irradiated at an irradiance of 0.1 W/cm(2) using a He-Ne laser in conjunction with a double integrating sphere system. Forward and back scattering of normal and malignant serum showed an exponential decrease in fluorescence amplitude. The results indicate that there is notable amplitude difference between malignant and normal blood serum with malignant blood serum showing decreased scattering. These results have important implications for photodiagnosis and photodynamic therapy.
Lasers in Medical Science 02/2010; 25(4):545-50. · 2.00 Impact Factor
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Laser Physics Letters 01/2010; 7:757-764. · 9.97 Impact Factor
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Laser Physics 01/2010; 20:1673-1678. · 3.61 Impact Factor
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Laser Physics Letters 01/2010; 7(12):889–898. · 9.97 Impact Factor
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Radiochimica Acta 01/2010; · 1.58 Impact Factor
