TY  - JOUR
A1  - Rancan, Fiorenza
A1  - Wiehe, Arno
A1  - Nöbel, Maria
A1  - Senge, Mathias O
A1  - Al Omari, Saleh
A1  - Böhm, Fritz
A1  - John, Matthias
A1  - Röder, Beate
T1  - Influence of substitutions on asymmetric dihydroxychlorins with regard to intracellular uptake, subcellular localization and photosensitization of Jurkat cells
N2  - The search for new efficient sensitizers for photodynamic therapy (PDT) points to improve photophysical properties like absorption in the red region and singlet oxygen quantum yield as well as to control the localization of the sensitizer within the tumour cell. Depending on their physicochemical properties and their uptake mechanism, sensitizers can reach different intracellular concentrations and localize in different subcellular compartments. Moreover, the preferential localization of a sensitizer in target organelles, like mitochondria or lysosomes, could determine the cell death mechanism after PDT. This study aimed to investigate the influence of substitutions on dihydroxychlorins with regard to intracellular uptake, subcellular localization and cell death pathway. Moreover, the effect of a liposome-based delivery system was tested. The intracellular uptake was found to be strictly dependent on the sensitizer molecular structure and the means of its delivery. The most polar sensitizer in this study (compound 3) had, depending on incubation time, an intracellular concentration 2-8 times higher than the unsubstituted chlorin 1. All investigated photosensitizers localize predominantly in lysosomes but after longer incubation times weak fluorescence intensity was also detected in mitochondria and Golgi apparatus. The cell death pathway was found to be influenced by the sensitizer intracellular concentration and the applied light doses. In general, the increasing amphiphilicity of the sensitizer molecules is correlated with an increased sensitizer uptake and an increased rate of necrotic cells after irradiation. (C) 2004 Elsevier B.V. All rights reserved
Y1  - 2005
SN  - 1011-1344
ER  - 
TY  - JOUR
A1  - Litwinski, Christian
A1  - Tannert, Sebastian
A1  - Jesorka, Aldo
A1  - Katterle, Martin
A1  - Roder, Beate
T1  - Photophysical properties of gallium hydroxyl tetratolylporphyrin and 13(2)-demethoxycarbonyl-(gallium hydroxyl)- methyl-pheophorbide alpha
N2  - Two metal tetrapyrroles containing gallium, gallium hydroxyl tetratolylporphyrin and 13(2)-demethoxycarbonyl- (gallium hydroxyl)methyl pheophorbide a (Ga-(OH)-chlorin), were synthesized from their respective free bases using Ga(III)-acetylacetonate in a phenol melt. Their photophysical properties were investigated and the quantum yields of different monomolecular deactivation processes were determined. For Ga-(OH)-porphyrin S-2-fluorescence was observed and quantified. In contrast. for Ga-(OH)-chlorin no S-2-fluorescence was observed. Both compounds should be useful as efficient photosensitizers in photodynamic therapy.
Y1  - 2006
UR  - http://www.sciencedirect.com/science/journal/00092614
U6  - https://doi.org/10.1016/j.cplett.2005.10.131
SN  - 0009-2614
ER  -