Antitumor therapeutic efficacy of photoactivated phthalocyanines ZnS4PC and AlS2PC in tumor-bearing mice

摘要

Abstract: The photosensitizer of choice in photodynamic therapy (PDT) is the hematoporphyrin derivative (Hpd). However, Hpd has many characteristics which make it less than an ideal photosensitizer. The sulfonated phthalocyanines represent a new group of interesting compounds that have a strong absorption in the red part of the spectrum at 675 nm. In our laboratory we compare the efficacy of two phthalocyanines, the zincum tetrasulfonated (ZnS$-4$/Pc) and the aluminum disulfonated (AlS$-2$/Pc), on a murine tumor. Mice bearing MS-2 fibrosarcoma were treated with 5 or 25 mg/kg of ZnS$-4$/Pc or AlS$-2$/Pc and then the tumor mass was exposed to a laser light (100 mW for 10'). The results show that the treatment with AlS$-2$/Pc is significantly more therapeutically active in respect to the treatment with the same dose of ZnS$-4$/Pc. Moreover, resistance to rechallenge with the MS-2 tumor was evidenced by surviving animals. Studies are in progress with other murine tumors with different biological properties. !10