SPECTRAL PROPERTIES OF THE PHTHALOCYANINES AND THEIR PHOTOTOXICITY
Hana Kolarova, Roman Kubínek, Miroslav Strnad
Centre of Molecular Biology and Medicine, Palacký University Olomouc,
Department of Biophysics, Faculty of Medicine, Palacký University, Olomouc, Czech Republic
E-mail: KOL@risc.upol.cz, KUBIN@risc.upol.cz
In photodynamic therapy (PDT), a sensitizer, light, and oxygen are used to cause photochemically induced cell´s death. The mechanism of phototoxicity involves generation of singlet oxygen and other free radicals when the lightexcited senzitizer loses or accepts an electron.
Efficiency of PDT is affected by factors included:
There are four properties that would make a sensitizer optimal for PDT.
Types of photosensibilisers
Phthalocyanines, chlorines and 5-aminolevulinic acid present a new generation of substances for photodynamic treatment of tumors.
Protoporphyrin IX production after systemic 5-aminolevulinic acid administration is very tissue specific.
Phthalocyanines can be chelated with a variety of metals, chiefly aluminium and zinc, and these diamagnetic metals enhance the phototoxicity. Less sulfonated compounds, which are more lipophilic, exhibit the best membrane-penetrating properties and are the most active.
To find optimal therapeutic doses for i. v. or local application, it was necessary to test:
Standard testing system for definition of the in vitro cytotoxicity and phototoxicity: