Photodynamic therapy in Argentina

Summary 

The use of endogenous Protoporphyrin IX generated through the heme biosynthetic pathway after administration of 5-aminolevulinic acid (ALA) has led to many applications in photodynamic therapy (PDT). In Buenos Aires, Argentina, the Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), reported for the first time, in 1975, porphyrin synthesis from ALA in highly dividing plant tissues. Increased porphyrin synthesis in tumours as well as cell photosensitisation was reported soon after. Our group is also interested in studying the use of new synthetic lipophilic derivatives of ALA as well as ALA delivery in liposomes. We have elucidated the mechanism of ALA transport in mammalian and yeast cells. The interactions between ALA-PDT and nitric oxide were investigated in three murine adenocarcinoma cell lines. In the National University of Río Cuarto, Córdoba, a group is devoted to the synthesis of new porphyrin-derived photosensitisers to study their effects on photoinactivation of bacterial and mammalian cells death by PDT. At the Centre of Electron Microscopy of the Cordoba National University, a prototype of a 630nm noncoherent light source was designed and constructed. Cost of the light source and scarce knowledge of the benefits of PDT by physicians limit the spread of the treatment throughout the country.

Abbreviations: ALA, 5-aminolevulinic acid, Me-ALA, ALA-methyl ester, DMSO, dimethylsulphoxide, GABA, γ-aminobutyric acid, He-ALA, ALA-hexyl ester, i.p., intraperitoneal, i.t., intratumour, THP-ALA, R, S-2-(hydroxymethyl)tetrahydropyranyl-ALA, PDT, photodynamic therapy, P-C60, porphyrin-C60 dyad, PpIX, Protoporphyrin IX, s.c., subcutaneous, Und-ALA, ALA-Undecanoyl ester, ZnPc 2, Zn(II) tetramethyltetrapyridinoporphyrazinium salt, ZnPc 1, Zn(II) tetrapyridinoporphyrazine

Keywords: ALA, 5-Aminolevulinic acid, PDT, Photodynamic therapy, History, Argentina