Liposomal Surface-Loading of Water-Soluble Cationic Iron(III) Porphyrins as Anticancer Drugs

A novel design of anticancer drug delivery system, based on an electrostatic binding of negatively charged liposomes and cationic metalloporphyrins under physiological conditions, is reported. A lack of cytotoxicity of the iron(III) porphyrin-loaded liposomes and an efficient generation of a toxic hydroxyl radical (OH<sup>•</sup>) from a superoxide anion radical (O<sub>2</sub><sup>-•</sup>) through the iron(III)-catalyzed dismutation and the Fenton-like reaction allow for a targeted necrosis of tumor cells where the concentration of O<sub>2</sub><sup>-•</sup> is locally increased as a result of the reduced activity of superoxide dismutase and catalase in these cells.Keywords: Anticancer drug delivery system; liposome; cationic metalloporphyrins; superoxide anion radical; hydroxyl radical