Design of red-emitting 1D zinc coordination polymer for targeted drug delivery to nucleus

Cell nucleus is considered as the ultimate target for various therapeutic agents in numerous disease treatments. Nucleus-targeted drug delivery systems are more effective in cancer chemotherapy, as over 75% of the commonly used chemotherapeutic drugs in clinic are acting on cell nucleus. Herein a novel 1D semiconducting zinc coordination polymer (Zn-QCDM) was designed with a reduced bandgap of 1.91 eV and bright red fluorescence. Because of the strong π-π stacking and Zn-O coordination with unpaired bases on RNA, the Zn-QCDM shows selective targeting of nucleoli with the selectivity over 40%. After loading camptothecin (CPT), a typical chemotherapeutic drug, the Zn-QCDM can effectively deliver the drug to nucleus, thereby significantly enhances the therapeutic effect. The inhibition rate of the Zn-QCDM loaded with CPT reaches 74% in mouse breast 4T1 tumor treatments, which is 29% higher than that of pristine CPT. This progress provides a paradigm in design of structure-precise drug carrier with clear targeting property as well as mechanism interpretation.