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1
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Circular Dichroism Spectra of Axially Oriented Rhodospirillum rubrum Cells and Their Fragments Immobilized in Polymer Film

100%
Cegielski R., Frąckowiak D., Liang J.
Acta Physica Polonica A
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1991
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vol. 79
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issue 4
479-491
EN
Circular Dichroism (CD) spectra of Rhodospirillum rubrum cells, and their fragments embedded in isotropic and uniaxially oriented by stretching polyvinyl alcohol films were measured. Effects responsible for CD signal generation such as assymetry of chromophores itself, the helical organisation of lamellar system, the helical texture of stretched PVA matrix, the contribution from circular and linear birefringence, as well as from exciton splitting resulting from pigments mutual interactions are discussed.
2
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Spectral properties of phthalocyanines incorporated into resting and stimulated human peripheral blood cells.

100%
Waszkowiak A., Frąckowiak D., Wiktorowicz K., Miyake J.
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2002
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vol. 49
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issue 3
633-641
EN
Human peripheral blood cells stimulated by phytohemagglutinin (which serve as a model of cancerous cells) and resting cells were incubated in dimethyl sulfoxide solutions of various phthalocyanines. In order to diminish the influence of atmospheric oxygen the cells were embedded in a polymer (polyvinyl alcohol) film. Fluorescence spectra of the samples were measured over two regions of excitation wavelengths: at 405 nm (predominant absorption of the cell material) and in the regions of strong absorption of phthalocyanines (at about 605 nm and 337 nm). The intrinsic emission of cell material became changed as a result both of cells' stimulation and of incubation of cells in dye solution. In most cases the stimulated cells when stained by dye exhibited higher long wavelength fluorescence intensity than resting cells. This suggests higher efficiency of dye incorporation into cancerous cells than into healthy cells. The absorption spectra of samples were also measured. The spectra of various phthalocyanines in incubation solvent, in polymer and in the cells embedded in polymer, were compared. The comparison of properties of the cells stimulated for different time periods enabled to establish the conditions of stimulation creating a population of cells incorporating a large number of sensitizing molecules.
3
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Incorporation of stilbazolium merocyanines into human leukocytes measured by flow cytometry

100%
Wiktorowicz K., Niedbalska M., Planner A., Frąckowiak D.
Acta Biochimica Polonica
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1995
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vol. 42
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issue 3
333-338
4
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The incorporation of various porphyrins into blood cells measured via flow cytometry, absorption and emission spectroscopy

100%
Ion R.-M., Planner A., Wiktorowicz K., Frąckowiak D.
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5
Content available remote

Preliminary studies of phthalocyanine sensitizers incorporated into human leukemia cells from two cell-lines.

88%
Wiktorowicz K., Cofta J., Dudkowiak A., Waszkowiak A., Frąckowiak D.
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vol. 51
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issue 3
703-710
EN
Three phthalocyanine dyes-sensitizers were incorporated into two types of human T leukemia cells from two cell-lines: CCRF and MOLT 4. The efficiency of the dye incorporation into cells and photochemical properties of stained cells were investigated using fluorescence spectroscopy. The dyes exhibited different properties in each of the two cell-lines. Small differences in cell membrane properties have a strong influence on the efficiency of dye incorporation and on the course of photodynamic reaction. It is suggested that, for a given patient, an optimal dye-sensitizer should be established before photodynamic treatment.
6
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Orientation and spectral properties of two stilbazolium merocyanine dyes in stretched and unstretched polyvinyl alcohol films

88%
Dudkowiak A., Frąckowiak D., Teślak E., Gryczyński Z., Gryczyński I.
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2007
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vol. 54
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issue 3
647-656
EN
Spectral properties (anisotropy coefficients calculated for absorption, emission and fluorescence decay time) of two stilbazolium merocyanine dyes have been determined to evaluate the applicability of these dyes as sensitizers in photodynamic therapy. The dyes were embedded in an anisotropic polymer matrix. Analysis of the emission decay components measured in polarized light provides information on the interactions of the dye molecules with the polymer matrix being a model of an anisotropic biological system. Different values of the emission anisotropies obtained from various polarized components of fluorescence decays have shown that the orientations of the dye molecules influence their interactions with the polymer. This means that differently oriented dye molecules located in biological systems should exhibit different interactions with membranes. The chain length and type of side groups attached as well as the salt form of the dye molecule were shown to influence the dye-polymer interactions and should be taken into account before the application of merocyanine dyes in medicine. These dyes seem to be promising optical sensors with spectral properties, including the calculated anisotropy coefficients, sensitive to the molecular environment, useful to study orientation and interaction with neighbouring molecules in biological membranes.
7
Content available remote

Incorporation of stilbazolium merocyanines into resting and stimulated mononuclear leukocytes

88%
Frąckowiak D., Wiktorowicz K., Cofta J., Niedbaiska M., Latosińska M.
Acta Biochimica Polonica
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1995
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vol. 42
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issue 1
61-68
8
Content available remote

The interactions of phthalocyanines with stimulated and resting human peripheral blood mononuclear cells.

76%
Frąckowiak D., Waszkowiak A., Manikowski H., Ion R.-M., Cofta J., Wiktorowicz K.
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2001
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vol. 48
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issue 1
257-269
EN
The interactions of two metal-free phthalocyanines [(H2Pc) and Solar Pc (with four peripherical groups: SO2N(CH2CH2OH)2)] and of one metal substituted dye (CoPc) with resting and stimulated human peripheral blood mononuclear cells (PBMC) were compared. The absorption, fluorescence, photoacoustic and EPR spectra of both resting cells and cells stimulated by phytohaemagglutinin, incubated in dimethyl sulfoxide (DMSO) with very low or 95% water content and with or without dye addition, were measured. The fate of the light absorbed by the samples was investigated. It is known that singlet oxygen production is crucial for photodynamic action of dyes. Thermal deactivation and luminescence emission compete with this process, so investigation of these alternative paths of sensitizer deactivation provides information about photodynamic action. The incorporation of the investigated dyes into cells and the perturbation of the cell structure caused by the dyes, the incubation solvent and the activator were investigated by comparing the spectral properties of PBMC before and after stimulation and incubation. Incubation of the cells for 1 h in a solution of Solar Pc in 99.5% aqueous DMSO, resulted in an efficient dye incorporation which was highly selective. Solar Pc being introduced much more efficiently into stimulated cells than into resting cells.
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