Novel Nanostructural Hybride Materials for Photodynamic Theraphy

Photodynamic theraphy (PDT) is a clinically approved method for treatment of cancer and some other diseases. It employs the combination of a drug (photosensitizer) and light to induce photoxicity towards the cancerous cells. The efficiency of currently used photosensitizers is limited due to their aggregation in aqueous media and low chemical purity; usually a mixture of various isomers is used. This paper presents the results of our studies on the development of nanostructural materials for PDT. They are constructed from porphyrin (Po) which is covalently attached to the chain of hydrophylic polymer such as poly(methacrylic acid) (PMA) or poly(ethylene glycol) (PEG) and solubilized in lipid bilayer of liposome vesicles. The attachment of Po to the polymer chain improves its solubility in water while the solubilization in liposome carriers helps the dye to penetrate the cell membranes. Physicochemical and photophysical properties of those systems were determined. The in vitro studies on cancer cell lines demonstrated that the photosensitizers are efficiently accumulated in the cells. Their dark toxicity is negligible, while phototoxicity is very high.