Two Zn(II) coordination polymers with anticancer drug norcantharidin as ligands for cancer chemotherapy

Here two Zn(II) coordination polymers [Zn20(DMCA)12]O12 (DMCA = demethylcantharic acid, DMCA-Zn1) and [Zn(DMCA)](H2O)2 (DMCA-Zn2) are synthesized from a broad-spectrum anticancer drug norcantharidin (NCTD) and Zn(NO3)2·6H2O under solvothermal conditions. By mechanical grinding with a biocompatible polymeric surfactant F127, ultrasonic treatment and filtration, DMCA-Zn1 and DMCA-Zn2 can be transformed into stable nanoparticles (DMCA-Zn1 NPs and DMCA-Zn2 NPs) suspended in water with average diameters of around 190 nm and 162 nm for drug delivery. The in vitro evaluation indicates that DMCA-Zn1 NPs and DMCA-Zn2 NPs can enter into HepG2 and Hep3B cancer cells via endocytosis and inhibit their proliferation. Meanwhile they exhibit relatively low toxicity to L927 normal cells. The in vivo evaluation confirms that DMCA-Zn1 NPs and DMCA-Zn2 NPs can more effectively inhibit the growth of Hep3B tumors with relatively few side effects compared with free NCTD. This approach can be extended to other anticancer drugs to construct nanodrug delivery systems for cancer treatment.