Development of Photoactivatable Ion Transporters for Photodynamic Anticancer Therapy

Abstract

The interest in developing small molecule-based synthetic ion transporters has been tremendous in recent times in supramolecular chemistry, providing a plethora of studies mainly focusing on the transport of chloride ions. However, this potential is not realized entirely due to the uninhibited action of such transporters in biological systems. Hence, external stimulus, especially light, helps in providing the required specificity to the ion transport system in the form of photo-irradiative ion transporters. Herein, we report a series of tolane-based ion-transporters and o-nitrobenzyl linked photo-cleavable pro-carrier molecules, where the former can transport anion via the antiport process confirmed from the valinomycin assay. Compound1bshowed the highest transport efficiency among the congeners across EYPC−LUVs⊃HPTS, and the synthesis and characterization of the pro-carrier molecule of that derivative were carried out. Ion selectivity studies reveal that compound 1b has the highest transport efficiency towards Cl− ion. The photo-cleavable property of compound 1' helps in enabling the selective photo-controlled release of the active carrier 1b, which can specifically initiate chloride-mediated apoptosis in cancer cells over healthy cells.