13 June 1989 Intracellular Distribution Of Porphyrin-Based Photosensitizers In In Vitro Cultured Human Bladder Tumor Cells.
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Proceedings Volume 1065, Photodynamic Therapy: Mechanisms; (1989) https://doi.org/10.1117/12.978021
Event: OE/LASE '89, 1989, Los Angeles, CA, United States
Abstract
The Increasing use of porphyrin-based compounds for photodynamic therapy raises concerns about the intracellular distribution of these substances in target cells. We are utilizing chlorophyll derivatives as photosensitizers and exploring their intracellular distribution in in vitro cultivated EJ human bladder tumor cells. The cells are exposed to these compounds delivered within a liposome-based carrier system as well as in the free form. High resolution subcellular fractionation approaches are employed to examine the cellular localization of the photodynamic agents. Free pheophorbide a and hematoporphyrin derivative localize, almost exclusively within the plasma membrane of cells exposed to the agents for 90 min. In contrast the pheophorbide a loaded liposomes are readily taken into lysosomes, presumably by endocytosis, if presented to the cells at 4° and then incubated with the cells at 37°. However cells exposed to the liposomes continuously at 37° accumulate the pheophorbide a in the plasma membrane. These studies indicate that untargeted liposomes exhibiting a decreased fusegenic tendency than employed in these studies may allow for an effective delivery of photodynamic agent to lysosomes.
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
R. D. Poretz, R. D. Poretz, I. Vucenik, I. Vucenik, L. Bergstrom, L. Bergstrom, A. Segelman, A. Segelman, G. Sigel, G. Sigel, S. Chernomorsky, S. Chernomorsky, } "Intracellular Distribution Of Porphyrin-Based Photosensitizers In In Vitro Cultured Human Bladder Tumor Cells.", Proc. SPIE 1065, Photodynamic Therapy: Mechanisms, (13 June 1989); doi: 10.1117/12.978021; https://doi.org/10.1117/12.978021
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