Localization of zinc(II)-phthalocyanine within implanted tumors after intravenous administration of a liposomal formulation

摘要

Abstract: The liposomal zinc(II) phthalocyanine (Zn-Pc) formulation CGP55847 was administered intravenously (0.5 mg Zn-Pc/kg) to C57/BL6 mice bearing subcutaneously implanted B16 melanomas or to Swiss mice bearing intramuscularly implanted Ehrlich carcinomas. Tumors were removed 3 or 24 h after dosing, and the Zn-Pc content and intratumoral distribution determined by extraction and quantitative fluorescence microscopy. Localization of the photosensitizer within the tumor mass occurred more rapidly in the highly vascularized Ehrlich carcinoma compared to the less highly vascularized B16 melanoma. Zn-Pc was evident in and around blood vessels 3 but not 24 h after dosing. More Zn-Pc was found in necrotic areas compared to viable tumor tissue; little or no Zn-Pc was detected in the muscle tissue invaded by the Ehrlich carcinoma. At the cellular level, Zn-Pc was associated with membranes and the cytosol but not the nucleus. !4