Photosensitizers for tumor fluorescence and phothodynamic therapy of cancer

Photosensitive dyes have great interest because of the attractive combination of fluorescence imaging and photochemical destruction of tumors. When detected early, tumors are more easy to treat, usually respond better to treatment and there is a reduced risk of spreading of the disease. If a reliable fluorescence detection technique were available it could be possible to "screen", on a routine basis, people who are at risk for developing a tumor. Drawbacks of photosensitizers like HPD and Photofrin® such as prolonged skin photosensitivity and low absorption at clinically relevant wavelengths lead to the search of new photosensitizers. A number of fluorescent dyes have been proposed as second generation photosensitizers. In this thesis 13 administered dyes and one endogenously generated dye will be discussed with respect fluorescence pharmacokinetics and photodynamic activity. An in vivo skin fold chamber model was used to study these properties.