An upconversion nanoparticle/Ru(II) polypyridyl complex assembly for NIR-activated release of a DNA covalent-binding agent

Photoactivated anticancer chemotherapy distinguishes itself by its high selectivity by virtue of the spatiotemporal control of irradiation. However, short photoactivation wavelengths limit its application. Herein, an amphiphilic Ru(II) complex, cis-[Ru(bpy)(2)(C18H37CN)(2)](2+) (bpy = 2,2'-bipyridine), was embedded along with a poly(ethylene glycol, PEG)-modified lipid onto the surfaces of oleate-capped lanthanide-doped upconversion nanoparticles (UCNPs). The resultant core-shell hybrid system is water-dispersible, stable in the dark, and releases a DNA covalent-binding agent of [Ru(bpy)(2)(H2O)(2)](2+) upon 980 nm laser irradiation, providing guidelines for developing near-infrared (NIR) light triggered chemotherapeutics.