Resumen de Ruthenium Phthlocyanines as potential photosensitizers for singlet Oxygen generation
The Photodynamic Therapy (PDT) combines light, molecular oxygen and a PS for the production of reactive oxygen species (ROS), such as 1O2 and free radicals, which will induce oxidative stress and, eventually, cell dead. This allows for the non-invasive, selective and localized destruction of tumor cells with reduced side effects. Phthalocyanines (Pcs) are promising compounds to be applied as PSs for singlet oxygen generation. However, a major drawback of these compounds is their low solubility in physiological environments. This can be overcome through functionalization of the macrocycle at the peripheral and/or axial positions with appropriate hydrophilic functions, such as carbohydrates and polyether chains. The introduction of axial ligands reduces their aggregation in solution, thus improving their 1O2 generation efficiency.
This work describes the synthesis of Ruthenium Phthalocyanines (RuPcs) to be applied as photosensitizers (PSs) for singlet oxygen generation. These RuPcs are endowed with suitable axial ligands, providing the required solubility and/or selectivity. In this respect, several pyridine or phosphine-based structures bearing charged functions, polyether chains, carbohydrate units or folic acid units were synthesized and further coordinated to the central ion of RuPcs. In addition, solubility in water is enhanced through peripheral functionalization of RuPcs with polyether chains. The photophysical properties of the prepared PSs, namely their solubility in water and their ability to generate singlet oxygen were studied. Furthermore, the PSs were also evaluated in vitro in bladder cancer cells with respect to their capability to be internalized by cancer cells and their toxic effects, both in the dark and upon activation by ligh
