Photosensitizing Properties of Free and Bound Uroporphyrin I
Most studies of the sensitized photooxidation of biomolecules have been carried out with the sensitizer in solution or, as in the case of many porphyrins, in the form of small aggregates suspended in the medium.1 Cells, however are not homogeneous; they consist of a wide variety of microenvironments with different physical-chemical properties. Thus most photosensitizers added to cellular systems, depending on their properties, would be expected to dissolve in particular microregions of the cells or bind to cellular macromolecules such as proteins, nucleic acids or carbohydrates.2 This could change the sensitizer properties, the efficiency of photosensitization and the sensitizing mechanism.2,3 Thus it is difficult to carry over information on photosensitizers as obtained in solution to the cellular-organismal level. One preliminary approach to this problem is to examine the photochemical behavior of photosensitizer molecules bound to surfaces to simulate the possible intracellular situation. The present paper describes a preliminary comparison of the photosensitizing properties of uroporphyrin I in aqueous solution and bound covalently to beads of an agarose gel.
KeywordsQuantum Yield Rose Bengal Furfuryl Alcohol Photosensitize Oxidation Photosensitize Property
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