Abstract. in the present study, a comparative photodynamic therapy (pdt) study was performed using the phthalocyanine derivatives, Znpc(Och 3 ) 4 and Znpc(cF 3 ) 4 , in a mouse tumor model, under identical experimental procedures. We studied the ablation of tumors induced by pdt. the end-point was to compare the photodynamic efficacy of ZnPc(OCH 3 ) 4 and Znpc(cF 3 ) 4 . Znpc(Och 3 ) 4 and Znpc(cF 3 ) 4 were administered intraperitoneally at a dose of 0.2 mg/kg body weight. the injections of drugs were carried out in Balb/c mice bearing subcutaneously inoculated lm2 mouse mammary adenocarcinoma. histological examination and serum biochemical parameters were used to evaluate hepatic and renal toxicity and function. phototherapeutic studies were achieved employing a light intensity of 210 J/cm 2 . after pdt, tumoral regression analyses were carried out, and the degree of tumor cell death was measured utilizing the vital stain Evan's blue. in this pilot study, we revealed that the cytotoxic effect of Znpc(Och 3 ) 4 after pdt led to a higher success rate compared to Znpc(cF 3 ) 4 -pdt when both were intraperitoneally injectioned. Both phthalocynanine derivatives were able to induce ablation in the tumors. in summary, these results demonstrate the feasibility of Znpc(Och 3 ) 4 -or Znpc(cF 3 ) 4 -pdt and its potential as a treatment for small tumors.
Introductionphotodynamic therapy (pdt) is a well-known procedure in the field of clinical medicine for the treatment of cancer, although there has also been research into its application for non-malignant disorders, such as psoriasis or actinic keratosis and for cases of choroidal neovascularization.the treatment is currently under active investigation for palliative or curative applications. pdt is an evolving cancer treatment that depends on three known and variable components: photosensitizer (pS), light and oxygen (1). pdt relies on selective accumulation of a pS in tumor tissue, which on illumination with light of appropriate wavelengths, generates reactive oxygen species, particularly singlet oxygen, and destroys tumor tissue (2). in recent years, treatment of cancer by pdt has gained considerable interest due to its intrinsic dual selectivity. the pS localizes in the malignant tissue, and the light is spatially focused on the lesion (3). phthalocyanines (pcs) are pSs of the dye family. pcs and their derivatives have been intensively investigated as the second generation pSs for pdt (4). most of the activity of clinical pSs in the dye family comes from phthalocyanines and their relatives, the naphthalocyanines. these structures are active in a range of 650-850 nm. most dyes are hydrophobic requiring delivery agents, such as a liposomal preparation, for clinical use. Linking dyes to a variety of metals improves efficacy. aluminum, zinc and silicon appear to offer the best pdt activity (5).the development of new compounds as potential pSs in PDT is of great scientific interest. The advantage of this therapy over available therapies is the high selectivity of tumor des...