A Lock ‐and‐Kill Anticancer Photoactivated Chemotherapy Agent

AbstractPhotosubstitutionally active ruthenium complexes show high potential as prodrugs for the photoactivated chemotherapy (PACT) treatment of tumors. One of the problems in PACT is that the localization of the ruthenium compound is hard to trace. Here, a ruthenium PACT prodrug, [Ru(3)(biq)(STF-31)](PF6)2, (where3 =  3-([2,2’:6’,2”-ter- pyridin]-4’-yloxy)propyl-4-(pyren-1-yl)butanoate) and biq = 2,2’-biquinoline), has been prepared, in which a pyrene tracker is attachedvia an ester bond. The proximity between the fluorophore and the ruthenium center leads to fluorescence quenching. Upon hydrolysis of the ester linkage, however, the fluorescence of the pyrene moiety is recovered, thus demonstrating prodrug cellular uptake. Further light irradiation of this molecule liberates by photosubstitution STF-31, a known cytotoxic nicotinamide phosphoribosyltransferase (NAMPT) inhibitor, as well as singlet oxygenvia excitation of the free pyrene chromophore. The dark and light cytotoxicity of the prodrug, embedded in liposomes, as well as the appearance of blue emission upon uptake, were evaluated in A375 human skin melanoma cells. The cytotoxicity of the liposome-embedded prodrug was indeed increased by light irradiation. This work realizes anin vitro proof-of-concept of the lock-and-kill principle, which may ultimately be used to design strategies aimed at knowing where and when light irradiation should be realizedin vivo.
Source: Photochemistry and Photobiology - Category: Science Authors: Tags: Special Issue Research Article Source Type: research