Topic
Protoporphyrin IX
About: Protoporphyrin IX is a research topic. Over the lifetime, 2250 publications have been published within this topic receiving 65544 citations. The topic is also known as: PpIX.
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TL;DR: Comparison with previously reported analogous data for heme proteins enables it to be suggested that the onset of substate interconversions in these latter systems can be reflected in motions of the iron atom with respect to the porphyrin plane.
Abstract: We report the thermal broadening of the Soret band in heme-CO, heme-OH and protoporphyrin IX in the temperature range 300–20 K. For protoporphyrin IX the temperature dependent Gaussian line broadening follows the behavior predicted by the harmonic approximation in the entire temperature range investigated. In contrast, for heme-CO and heme-OH the harmonic behavior is obeyed only up to about 180 K and an anomalous line broadening increase is observed at higher temperatures. This effect is attributed to the onset of anharmonic motions of the iron atom with respect to the porphyrin plane. Comparison with previously reported analogous data for heme proteins enables us to suggest that the onset of substate interconversions in these latter systems can be reflected in motions of the iron atom with respect to the porphyrin plane.
26 citations
TL;DR: It is shown that sublethal PDT of human WiDr adenocarcinoma cells and D54Mg glioblastoma cells with 5-aminolevulinic acid, disulfonated tetraphenylporphyrine, or MitoTracker Red inhibits their trypsin-induced detachment from a plastic substratum.
26 citations
TL;DR: In this paper, the authors describe the solubilization/dispersion of as-produced and purified single-walled carbon nanotubes (raw-SWNTs) with protoporphyrin IX derivatives and tetraphenylporphyrin iron(III) chloride.
Abstract: We describe the solubilization/dispersion of as-produced and purified single-walled carbon nanotubes (raw-SWNTs and p-SWNTs) with protoporphyrin IX derivatives and tetraphenylporphyrin iron(III) chloride, the spectral behavior of the octaalkylporphyrins-solubilized shortened-SWNTs (s-SWNTs), and the electrochemistry of a p-SWNTs/FePP cast film on a glassy carbon electrode. Transmission electron and atomic force microscopies, as well as UV-visible-near IR spectroscopy, revealed that the protoporphyrin IX derivatives individually dissolved the p-SWNTs in polar solvents under mild conditions of sonication using a bath-type sonicator, followed by centrifugation at 1000 g. The raw-SWNTs were more easily dissolved than the p-SWNTs with protoporphyrin IX zinc(II) (ZnPP), whereas the amount of the solubilized/dispersed p-SWNTs did not depend on the concentration of the solubilizer and sonication time. The absorption and fluorescence spectral measurements of the octaalkylporphyrins in dimethylformamide containing 1 vol% tetrahydrofuran with various amounts of the s-SWNTs showed that the absorption maxima of the octaalkylporphyrins decreased with an increase in the concentration of the s-SWNTs without wavelength shift and the fluorescence of the porphyrins was quenched by the addition of the s-SWNTs. These spectral behaviors are direct evidence for the interaction between the nanotube sidewall and the porphyrins in the solutions. The cyclic voltammograms of the p-SWNTs/hemin (FePP) and free hemin (FePP) suggest that the nanotubes act as a conduction passage for electrons between hemin (FePP) and the glassy carbon electrode.
26 citations
TL;DR: A strong correlation between local PpIX photobleaching during illumination and the fluorescence intensity 1 h after illumination similar to what the authors have observed in patients treated with ALA-PDT is found, concluding that the increase in Ppix fluorescence after illumination is due to local cellular re-synthesis.
Abstract: Protoporphyrin IX (PpIX) fluorescence that is bleached during aminolevulinic acid (ALA) mediated photodynamic therapy (PDT) increases again in time after treatment In the present study we investigated if this increase in PpIX fluorescence after illumination is the result of local re-synthesis or of systemic redistribution of PpIX We studied the spatial distribution of PpIX after PDT with and without cooling using the skin-fold observation chamber model We were unable to show a correlation between the local PpIX fluorescence increase and the distance from a blood vessel The spatial distribution of PpIX fluorescence within normal tissue or tumour is not changed in response to the illumination These observations suggest that there is no diffusion of PpIX into the treated tissue Cooling the tissue to 12 °C, a temperature at which PpIX synthesis is inhibited, inhibited the PpIX fluorescence increase normally observed after illumination We also found a strong correlation between local PpIX photobleaching during illumination and the fluorescence intensity 1 h after illumination similar to what we have observed in patients treated with ALA-PDT Therefore we conclude that the increase in PpIX fluorescence after illumination is due to local cellular re-synthesis
26 citations
TL;DR: In this paper, the influence of solvent polarity, viscosity, concentration, temperature, and pH medium on the photophysical properties of protoporphyrin IX, pyropheophorbide-a, and Photofrin® were investigated by UV-visible absorption, fluorescence emission, singlet oxygen emission, and time-resolved fluorescence spectroscopies.
Abstract: Photodynamic therapy (PDT) is an innovative treatment of malignant or diseased tissues The effectiveness of PDT depends on light dosimetry, oxygen availability, and properties of the photosensitizer (PS) Depending on the medium, photophysical properties of the PS can change leading to increase or decrease in fluorescence emission and formation of reactive oxygen species (ROS) especially singlet oxygen (1O2) In this study, the influence of solvent polarity, viscosity, concentration, temperature, and pH medium on the photophysical properties of protoporphyrin IX, pyropheophorbide-a, and Photofrin® were investigated by UV-visible absorption, fluorescence emission, singlet oxygen emission, and time-resolved fluorescence spectroscopies
26 citations