PEG-containing ruthenium phthalocyanines as photosensitizers for photodynamic therapy: synthesis, characterization and in vitro evaluation

Abstract

Three ruthenium(II) phthalocyanines functionalized at their axial positions with 4–12 PEG chains bearing hydroxy, amino and ether terminal groups were synthesized and studied as PDT agents against bladder cancer cells. All three dyes displayed high singlet oxygen generation quantum yields in DMSO (Φ_Δ = 0.76). The water-soluble Ru(L3)₂Pc also shows high singlet oxygen quantum yields (Φ_Δ = 0.48) in neat water. In vitro studies show that these complexes are accumulated in bladder cancer cells, are nontoxic PSs per se, and have high phototoxic efficiency.