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

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 (ΦΔ = 0.76). The water-soluble Ru(L3)2Pc also shows high singlet oxygen quantum yields (ΦΔ = 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.