作者： Yingqin Hou†, Yaoyi Wang†, Ruijue Wang§, Weier Bao‡, Xiaobo Xi‡, Yunlong Sun†, Shengtao Yang§ , Wei Wei‡, and Hua Lu†

† Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People’s Republic of China

‡ State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 10090, People’s Republic of China

§ College of Chemistry and Environment Protection Engineering, Southwest University for Nationalities, Chengdu 610041, People’s Republic of China

摘要：To improve the therapeutic index of cisplatin (CDDP), we present here a new paradigm of drug-induced self-assembly by harnessing phosphato-platinum complexation. Specifically, we show that a phosphato-platinum cross-linked micelle (PpY/Pt) can be generated by using a block copolymer methoxy-poly(ethylene glycol)-block-poly(l-phosphotyrosine) (mPEG-b-PpY). Coating of PpY/Pt with a R9-iRGD peptide by simple mixing affords a targeting micelle with near neutral-charged surface (iPpY/Pt). The micelles feature in well-controlled sizes below 50 nm and high stability under physiological conditions, and can withstand various environmental stresses. Importantly, the micelles demonstrate on-demand drug release profiles in response to pathological cues such as high ATP concentration and acidic pH. In vitro, the micelles are efficiently internalized and almost equally potent compared to CDDP. Moreover, iPpY/Pt induce greater cytotoxicity than PpY/Pt in a 3D tumor spheroid model likely due to its deeper tumor penetration. In vivo, the micelles exhibit prolonged circulation half-lives, enhanced tumor accumulation, excellent tumor growth inhibition in a xenograft HeLa model and an orthotropic mammary 4T1 model, and improved safety profiles evidenced by the reduced nephrotoxicity. Together, this work demonstrates for the first time that phosphato-platinum complexation can be exploited for effective delivery of CDDP, and suggests a paradigm shift of constructing nanosystems for other anticancer metallodrugs.