文献名： ROS-sensitive thioketal-linked polyphosphoester-doxorubicin conjugate for precise phototriggered locoregional chemotherapy

作者： Pei Pei^a, Chunyang Sun^b, Wei Tao^a, Jie Li^a, Xianzhu Yang^a,c, Jun Wang^c,d,f

^aSchool of Biological and Medical Engineering, Hefei University of Technology, Hefei, Anhui, 230009, PR China

^bDepartment of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, 300052, PR China

^cInstitutes for Life Sciences, School of Medicine, South China University of Technology, Guangzhou, Guangdong, 510006, PR China

^dNational Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong, 510006, PR China

^fGuangdong Key Laboratory of Nanomedicine, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, PR China

摘要：Minimizing drug leakage at off-target sites and triggering sufficient drug release in tumor tissue are major objectives for effective nanoparticle (NP)-based cancer therapy. The current covalent and cleavable drug-NP conjugation strategy is promising but lacks high controllability to realize tumor-specific release. As a proof-of-concept, the reactive oxygen species (ROS)-activatable thioketal (TK) bond was explored as the linkage between doxorubicin (DOX) and polyphosphoester (PPE-TK-DOX). The Ce6@PPE-TK-DOX NPs constructed by co-self-coassembly of PPE-TK-DOX and the photosensitizer Ce6 efficiently prevented premature drug leakage in the off-target tissue and cells because of the high stability of the TK bond under physiological conditions. Once circulating into the tumor site, the 660-nm red light was precisely employed to irradiate the tumor area under the guidance of fluorescence/magnetic resonance (MR) dual-model imaging, which can induce localized ROS generation, resulting in rapid cleavage of the TK bond. Consequently, the DOX prodrug was locoregionally released and activated, achieving tumor-specific drug delivery with high controllability by light. Such phototriggered prodrug release and activation at the desired site significantly enhanced the therapeutic efficacy and minimized the side effect, providing new avenues to develop drug delivery systems for remote on-demand drug delivery in vivo.