Photophysical properties of Zn(II) incorporated into liposomes

Amphiphilic phthalocyanines are used as potential photosensitizers in photodynamic therapy. The low water solubility of most of these dyes is the reason that different kinds of vehicles are employed as endogenous carriers. Due to the photophysical inactivity of the phthalocyanine aggregates, it is important to improve their solubility in order to study dyes in solid tumor models. On the other hand, the photodynamic therapy activity depends on the location of phthalocyanines in the cell and the interaction of cellular components. In this work, the photophysical properties of tetrasubstituted Zn(II) phthalocyanines with different lipophilic properties are incorporated into liposomes of L-alpha-dimyristoylphosphatidylcholine (DMPC). The fluorescence quantum yields, the association constants and their localization in the membranes are reported. Copyright (C) 2002 Society of Porphyrins & Phthalocyanines.