Fluorescent Self-Assembled Complexes Based on Glyco-Functionalized G-Quadruplexes as a Targeted Delivery Platform

Targeted delivery systems combined with the stimuli-responsive release of drug molecules hold noteworthy promise for precision medicine, enabling treatments with enhanced effectiveness and reduced adverse effects. An ideal drug delivery platform with versatile targeting moieties, the capability of combinational payloads, and simple preparation is highly desirable. Herein, we developed pH-sensitive fluorescent self-assembled complexes (SACs) of a galactose-functionalized G-quadruplex (G4) and a coumarin carboxamidine derivative as a targeted delivery platform through the nanoprecipitation method. These SACs selectively targeted hepatocellular carcinoma (HepG2) cells in fluorescence imaging after a short incubation and exerted specific anticancer effects in an appropriate dose range. Co-delivery of 1 μM prodrug floxuridine oligomers and 16 μg/mL SACs (minimal hemolytic effect) significantly reduced the cytotoxicity of the nucleoside anticancer drug on normal cells (NIH/3T3), kept up to 70% alive after 72-h incubation, and improved anticancer efficacy compared to SACs alone. This strategy can be extended to ratiometric multidrug delivery through self-assembly for targeted combinational therapy.