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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.


Papers
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Journal ArticleDOI
TL;DR: The findings suggest that PDT based on the accumulation of PpIX in the synovial membrane may be a rational basis for photodynamic synovectomy in arthritic diseases.
Abstract: Keywords: Photomedicine group Reference LPAS-ARTICLE-2002-003doi:10.1002/art.10199View record in Web of Science Record created on 2007-07-20, modified on 2016-08-08

39 citations

Journal ArticleDOI
TL;DR: This demonstrated use of endogenous fluorescence stimulation from aminolevulinic acid (ALA) and provides the first in vivo demonstration of deep tissue tomographic imaging with protoporphyrin IX, which is demonstrated using a noncontact single-photon counting fan-beam acquisition system interfaced with microCT imaging.
Abstract: Tomographic imaging of a glioma tumor with endogenous fluorescence is demonstrated using a noncontact single-photon counting fan-beam acquisition system interfaced with microCT imaging. The fluorescence from protoporphyrin IX (PpIX) was found to be detectable, and allowed imaging of the tumor from within the cranium, even though the tumor presence was not visible in the microCT image. The combination of single-photon counting detection and normalized fluorescence to transmission detection at each channel allowed robust imaging of the signal. This demonstrated use of endogenous fluorescence stimulation from aminolevulinic acid (ALA) and provides the first in vivo demonstration of deep tissue tomographic imaging with protoporphyrin IX.

39 citations

Journal ArticleDOI
TL;DR: The present results facilitate studies of ROS-mediated signalling in imaging-based single cell experiments by inferring that singlet oxygen, O2(a(1)Δg), is one ROS produced upon irradiation of PpIX under these conditions, and it is possible that the superoxide ion may also play a role in this system.
Abstract: Two-photon excitation of a sensitizer with a focused laser beam was used to create a spatially-localized subcellular population of reactive oxygen species, ROS, in single HeLa cells. The sensitizer used was protoporphyrin IX, PpIX, endogenously derived from 5-aminolevulinic acid delivered to the cells. Although we infer that singlet oxygen, O2(a1Δg), is one ROS produced upon irradiation of PpIX under these conditions, it is possible that the superoxide ion, O2−˙, may also play a role in this system. With a “high” dose of PpIX-sensitized ROS, the expected death of the cell was observed. However, under “low dose” conditions, clear signs of cell proliferation were observed. The present results facilitate studies of ROS-mediated signalling in imaging-based single cell experiments.

39 citations

Journal ArticleDOI
TL;DR: Fluentcein diacetate uptake and conversion to fluorescein indicated intracellular non-specific esterase activity, implying that ALA-ME conversion to ALA can occur.
Abstract: This study was carried out to test the hypothesis that induction of intracellular porphyrin synthesis by delta-aminolaevulinic acid (ALA) used to sensitize cells in photodynamic therapy would be more efficient if the ALA was used in an esterified form. Contrary to expectation, the generation of tetrapyrroles (TP) by cultured epithelial cells (CNCM-I-221) exposed to equimolar concentrations (0.6 mM) of ALA or its methyl ester (ALA-ME) showed that the mean total TP production rate during 6 h incubation in serum-free medium was 0.13 fmol cell(-1) h(-1) for ALA-exposed cells compared with 0.04 fmol cell(-1) h(-1) for cells exposed to ALA-ME. Fluorescein diacetate uptake and conversion to fluorescein indicated intracellular non-specific esterase activity, implying that ALA-ME conversion to ALA can occur. Cells exposed to ALA-ME exhibited loss of a greater proportion of total tetrapyrroles in the form of extracellular protoporphyrin IX (PPIX; 22.8%) compared with 11.6% in ALA-treated cells with a corresponding reduction in cell-associated PPIX (P < 0.05). A variable initial elevation in haem levels in ALA-ME-treated cells was observed, but did not reach statistically significant levels.

39 citations

Journal ArticleDOI
TL;DR: In this paper, the microstructure and magnetic properties of magnetic nanoparticles were characterized by XRD, TEM, FT-IR, and VSM, and it was found that the nanoparticles have high crystallinity with distinct lattices and the magnetic measurements reveal their well-defined superparamagnetic behavior at room temperature.

39 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202383
2022132
202157
202061
201958
201858