Fluorescence induction of protoporphyrin IX by a new 5‐aminolevulinic acid nanoemulsion used for photodynamic therapy in a full‐thickness ex vivo skin model

Please cite this paper as: Fluorescence induction of protoporphyrin IX by a new 5‐aminolevulinic acid nanoemulsion used for photodynamic therapy in a full‐thickness ex vivo skin model. Experimental Dermatology 2010; 19 : e302–e305. Abstract: An ex vivo porcine skin model was utilized to analyse the penetration of 5‐aminolevulinic acid (5‐ALA) contained in a nanoemulsion‐based formulation BF‐200 ALA (10% 5‐ALA‐hydrochloride) versus 16% aminolevulinate methyl ester‐hydrochloride in a commercially cream (MAL cream) by fluorescence microscopy of their common metabolite protoporphyrin IX (PpIX) after 3, 5, 8 and 12 h. Fluorescence signals of PpIX in pig skin treated with BF‐200 ALA were stronger than those for MAL cream. At 8 and 12 h, the PpIX fluorescence signals were 4.8‐ and 5.0‐fold higher than those measured after MAL cream application. Fluorescence signals of PpIX after application of BF‐200 ALA were detected in deeper tissue layers of the epidermis than after application of MAL cream (97.2 ± 5.7 μm for BF‐200 ALA vs 42.0 ± 4.2 μm for MAL cream). These data implicate that BF‐200 ALA in photodynamic therapy might lead to a superior therapeutically effect of intraepidermal (in situ) squamous cell carcinomas.