Water-soluble amphiphilic ruthenium(II) polypyridyl complexes as promising photodynamic therapy agents with nanomolar activity

Two new highly water-soluble amphiphilic Ru(II) polypyridyl complexes containing N-1,10-phenanthrolin-5-yldocosanamide and either 1,10-phenanthroline (phen, 1) or 1,4,5,8-tetraazaphenan-threne (TAP, 2) as ligands were synthesised and their photophysical and photobiological properties evaluated. Both complexes showed a rapid cellular uptake and displayed phototoxicity against HeLa cervical cancer cells revealing these complexes as promising photodynamic therapy (PDT) agents; with IC50 value of 2 μM for 2, while 1 is unusally activity, with nnanomlar activity; with ROS generation as the main mechanism.