TY - GEN
T1 - Comparative studies of selected porphyrin photosensitizers
AU - Johnson, F. M.
AU - Ehrenberg, B.
AU - Gross, E.
PY - 1990
Y1 - 1990
N2 - We wish to report on PDT simulation studies of a class of compounds, which because of their commercial nonavailability, had hitherto been overlooked: the tetrabenzoporphyrins (TBPs). We have studied absorption and fluorescence of these compounds in homogeneous solutions and in liposome vesicles. Each substance was examined for its photodynamic effects on 9,10-dimethylanthracene (DMA, an effective probe for singlet oxygen in PDT simulation). Since TBPs display absorption in the 630 nm region, a 15 mW He-Ne laser proved convenient for these studies. All our data were intercorrelated and compared with standard HPD and Photofrin samples, as well as studies of self-destruction of these chromophores under similar light irradiation conditions. Despite the fact that some TBPs such as MgTBP and ZnTBP have strong absorption bands in the 630 nm region (orders of magnitude greater than HPD), we found that other physical factors may play a dominant role in PDT effectiveness. We followed the photosensitization of DMA in real time by monitoring its fluorescence decrease at 457 nm and found that DMA undergoes an oxygen-mediated (type II) photosensitization reaction. ZnTBP was found to be the most efficient photosensitizer followed by PF-II, MgTBP, HPD and ZnPC. The partition coefficients of the sensitizers to lecithin liposomes are also reported.
AB - We wish to report on PDT simulation studies of a class of compounds, which because of their commercial nonavailability, had hitherto been overlooked: the tetrabenzoporphyrins (TBPs). We have studied absorption and fluorescence of these compounds in homogeneous solutions and in liposome vesicles. Each substance was examined for its photodynamic effects on 9,10-dimethylanthracene (DMA, an effective probe for singlet oxygen in PDT simulation). Since TBPs display absorption in the 630 nm region, a 15 mW He-Ne laser proved convenient for these studies. All our data were intercorrelated and compared with standard HPD and Photofrin samples, as well as studies of self-destruction of these chromophores under similar light irradiation conditions. Despite the fact that some TBPs such as MgTBP and ZnTBP have strong absorption bands in the 630 nm region (orders of magnitude greater than HPD), we found that other physical factors may play a dominant role in PDT effectiveness. We followed the photosensitization of DMA in real time by monitoring its fluorescence decrease at 457 nm and found that DMA undergoes an oxygen-mediated (type II) photosensitization reaction. ZnTBP was found to be the most efficient photosensitizer followed by PF-II, MgTBP, HPD and ZnPC. The partition coefficients of the sensitizers to lecithin liposomes are also reported.
UR - http://www.scopus.com/inward/record.url?scp=0025551311&partnerID=8YFLogxK
U2 - 10.1117/12.17672
DO - 10.1117/12.17672
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AN - SCOPUS:0025551311
SN - 0819402443
SN - 9780819402448
T3 - Proceedings of SPIE - The International Society for Optical Engineering
SP - 266
EP - 280
BT - Proceedings of SPIE - The International Society for Optical Engineering
PB - Publ by Int Soc for Optical Engineering
T2 - Proceedings of Photodynamic Therapy: Mechanisms II
Y2 - 16 January 1990 through 17 January 1990
ER -