| Abstract |
Pyridyl ligands with one ketal-protected carbohydrate unit (glucofuranose, galactopyranose or mannofuranose) were coordinated to the axial positions of ruthenium phthalocyanines (RuPc) in order to target the macrocycles to tumor cells. The biocompatibility of the resulting photosensitizers (PS) was enhanced by increasing their solubility in water through their peripheral and/or axial functionalization with polyether chains (PEG). All compounds generated singlet oxygen, with peripherally unsubstituted phthalocyanines displaying higher O-1(2) yields. Invitro assays using the human bladder cancer cell line HT-1376 revealed that peripherally unsubstituted phthalocyanines were also more efficient in terms of cellular uptake and therefore, phototoxicity. The protected carbohydrate functional groups at the axial positions did not improve significantly the cellular uptake of PSs, although they increased their photodynamic efficiency. Overall, mixed RuPcs functionalized with one carbohydrate unit at one of the axial positions and two PEG units at the other axial site showed promising properties as photosensitizers for photodynamic therapy applications and low toxicity in the dark. |
