Topical application of a novel porphycene dye for photodynamic therapy: penetration studies in human perilesional skin and basal cell carcinoma

摘要

Abstract: PDT in dermatology is of growing interest and there areefforts to develop new sensitizers for topicalapplication. Penetration potency of9-acetoxy-2,7,12,17-tetrakis-($beta@-methoxyethyl)-porphycene (ATMPn), a novel sensitizerfor topical photodynamic therapy, was studied inperilesional normal human skin from 58 melanomapatients and basal cell carcinomas of 12 patients.Single specimens of freshly excised perilesional skin(n equals 368) and basal cell carcinomas (n equals 28)were evaluated after topical application of an ATMPnsolution for different time intervals (2, 6, 16 h) andsubsequent preparation of cryostate sections (10micrometer). Fluorescence distribution in tissuesections was estimated qualitatively using a scoresystem respecting the morphological structure of humanskin. In all examined sections of perilesional skin redfluorescence indicative of ATMPn was seen down to thebasal layer of the epidermis using epifluorescencemicroscopy and optical multichannel analysis. Longerincubation times (16 - 20 h) revealed significanthigher score sums as compared to incubation times of 2or 6 h. However, basal cell carcinomas did not showtime dependent differences in penetration. After 6 hpenetration of ATMPn into the tumor, cell nests in thedeep dermis were detected. These results indicate thatthere might be a faster penetration of this sensitizerin tumorous tissue as in normal tissue after topicalapplication. !9