Comparative studies of selected porphyrin photosensitizers

F. M. Johnson, B. Ehrenberg, E. Gross

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

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.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Pages266-280
Number of pages15
ISBN (Print)0819402443, 9780819402448
DOIs
StatePublished - 1990
EventProceedings of Photodynamic Therapy: Mechanisms II - Los Angeles, CA, USA
Duration: 16 Jan 199017 Jan 1990

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume1203
ISSN (Print)0277-786X

Conference

ConferenceProceedings of Photodynamic Therapy: Mechanisms II
CityLos Angeles, CA, USA
Period16/01/9017/01/90

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