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PHOTOBLEACHING OF PHOTOFRIN II AS A MEANS OF ELIMINATING SKIN PHOTOSENSITIVITY *
Author(s) -
Boyle D. G.,
Potter W. R.
Publication year - 1987
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1987.tb04883.x
Subject(s) - photosensitivity , photobleaching , daylight , phototoxicity , medicine , photodynamic therapy , sunlight , chemistry , materials science , biochemistry , optoelectronics , physics , quantum mechanics , astronomy , optics , in vitro , fluorescence , organic chemistry
One of the effects of using Photofrin II as a sensitizer in clinical photodynamic therapy is skin photosensitivity. Avoiding the harmful effect of this photosensitivity typically requires the patient to remain indoors during daylight hours for 4 weeks post injection. Photosensitivity can last up to 8 weeks. A possible method of quickly eliminating skin photosensitivity is the use of photobleaching to eliminate the DHE (dihematoporphyrin ether, the active agent in Photofrin II) from the skin. The Photofrin II was used as supplied (Photomedica, Raritan, NJ) and will be referred to as DHE. We report a series of experiments using Swiss mice which demonstrate the ability to reduce the period of photosensitivity to 1 week. The Swiss mice received 5 mg kg ‐1 DHE intraperitoneal. Beginning at 24 h post injection they were given daily increasing light doses starting with 18 J cm ‐2 (at 630 nm). Only the left hind feet were treated with light. At 7 days post injection both hind feet were treated with 135 J cm ‐2 . The pretreated left foot showed no reaction to this treatment whereas the right foot reacted as strongly as control mice which had received no pretreatment with light. The control mice were also injected 7 days prior to treatment. As a check for tolerance animals received a second injection of 5 mg kg ‐1 DHE intraperitoneally 96 h after the conclusion of the bleaching protocol. Twenty‐four h later the left hind foot (previously desensitized by light) reacted to 135 J cm ‐2 as strongly as controls which had received the 5 mg kg ‐1 of DHE but no pretreatment.