Session Speaker

Development of Photodynamic Therapy for Larger Superficial Skin Mycoses
Threes Smijs, Joke Bouwstra and Stan Pavel
The Netherlands

Superficial mycoses of the skin (dermatophytoses) belong to the most frequently occurring human infections. Current treatments are largely based on the inhibition of ergosterol synthesis in growing hyphae. These treatments require a long-lasting application of antimycotics. However, the sensitivity of spores to these treatments is limited. In order to develop an effective treatment that would also target the spores, we examined the susceptibility of Trichophyton rubrum, one of the frequent causative agents, to photodynamic treatment. For that purpose, we utilized several synthetic porphyrin photosensitizers. From the examined photosensitizers, Sylsens B has shown the highest success rate. Its therapeutic effectiveness was dependant on pH and the molarity of its solution. The results obtained during in-vitro experiments were later confirmed on our newly developed ex-vivo model. This model makes use of T. rubrum grown on isolated human stratum corneum. The susceptibility of T. rubrum could be examined in different fungal growth stages. With the use of long-wave UV source we achieved complete fungal killing within several minutes. We can conclude that the development of the efficient single-step therapy of dermatophytoses based on phototherapeutic principles is quite feasible.