Photodynamic Tumor Therapy Using Singlet Oxygen

7 Photodynamic Tumor Therapy Using Singlet Oxygen 

The most common porphyrins used in this tumor therapy are protofrin and verteporfin having the generalized porphyrin structure (Fig. 6.14). It is extensively used in the treatment of oesophageal and lung cancer. 

The energy transfer process takes place in the following steps  

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Singlet oxygen generation is used in photodynamic tumor therapy—for instance, with porphyrins as photosensitizers. (Cf. Dougherty, 1992.) The disadvantage of natural porphyrins such as hematoporphyrin is that they are of low chemical stability and have an absorption spectrum similar to that of... 

On one hand, Cgo and its derivatives are considered promising materials for biological uses. The farthest progress has been made in experiments on its employment as sensitizer for the photochemical generation of singlet oxygen. The latter shall serve to the directed degradation of DNA or to the destruction of tumor tissue (photodynamic therapy). On the other hand, it is the electronic properties of the... 

Amphiphilic porphyrins, e.g., hematoporphyrins (photofrin) or chlorin (aspartyl amide) derivatives, are used in photodynamic therapy of tumors using red laser light. They tend to accumulate in tumor cells when injected intravenously, can be regioselectively irradiated via thin optical fibers, and then produce toxic singlet oxygen upon irradiation. Most useful are porphyrins with... 

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