NIR phosphorescent cyclometalated platinum (II) complexes with CAIX targeted and nuclear penetration as potent anticancer theragnostic agents.

Although cisplatin drugs have achieved great success in cancer therapy, they also easily cause drug resistance and other side effects. Non-classical platinum (II) complexes with targeted therapy characteristics have become one of the hotspots in the research of new anticancer drugs. In the present work, a series of carbonic anhydrase IX (CAIX)-targeted and inhibited cyclometalated platinum (II) complexes with near-infrared (NIR) phosphorescent emission have been developed, due to the calculation of Molecular docking and the result of CAIX inhibition assay in vitro, all complexes show a high binding affinity and effective inhibition on CAIX in vitro. Moreover, Pt2 shows a significant cellar uptake efficiency, and translocation of red emission in Pt2 from the cytoplasm to nuclear in Hela cell can be recorded by confocal within 24 h, while Pt2 can selectively target and locate in the lysosome of MDA-MB-231 cell, thus resulting in significantly enhanced therapeutic effect on multiple cancer cell lines compared with cisplatin, as well as the killing selectivity towards cancer cell of CAIX-inhibited cyclometalated platinum (II) complex are 6.0-14.6 times higher than that of cisplatin. Hence, our work presents the rational design of Pt (II)-CAIX conjugates as a promising strategy in the application of constructing a new platform for cancer theragnostic agents.