Enhancing the ROS generation ability of a rhodamine-decorated iridium(iii) complex by ligand regulation for endoplasmic reticulum-targeted photodynamic therapy

Lihua Zhou; Fangfang Wei; Jingjing Xiang; Hongfeng Li; Chunbin Li; Pengfei Zhang; Chuangjun Liu; Ping Gong; Lintao Cai; Keith Man-Chung Wong

doi:10.1039/d0sc04751a

Enhancing the ROS generation ability of a rhodamine-decorated iridium(iii) complex by ligand regulation for endoplasmic reticulum-targeted photodynamic therapy

Chem Sci. 2020 Oct 12;11(44):12212-12220. doi: 10.1039/d0sc04751a.

Authors

Lihua Zhou^{1

2}, Fangfang Wei³, Jingjing Xiang¹, Hongfeng Li¹, Chunbin Li¹, Pengfei Zhang¹, Chuangjun Liu^{3

4}, Ping Gong¹, Lintao Cai¹, Keith Man-Chung Wong³

Affiliations

¹ Guangdong Key Laboratory of Nanomedicine, Shenzhen Engineering Laboratory of Nanomedicine and Nanoformulations, CAS Key Lab for Health Informatics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences Shenzhen 518055 P. R. China ping.gong@siat.ac.cn pf.zhang@siat.ac.cn.
² School of Applied Biology, Shenzhen Institute of Technology No. 1 Jiangjunmao Shenzhen 518116 P. R. China.
³ Department of Chemistry, Southern University of Science and Technology 1088 Xueyuan Blvd. Shenzhen 518055 P. R. China keithwongmc@sustech.edu.cn.
⁴ College of Chemistry and Pharmaceutical Engineering, Huanghuai University 463000 Zhumadian China liuchuangjun@huanghuai.edu.cn.

Abstract

The endoplasmic reticulum (ER) is a very important organelle responsible for crucial biosynthetic, sensing, and signalling functions in eukaryotic cells. In this work, we established a strategy of ligand regulation to enhance the singlet oxygen generation capacity and subcellular organelle localization ability of a rhodamine-decorated iridium(iii) complex by variation of the cyclometallating ligand. The resulting metal complex showed outstanding reactive oxygen species generation efficiency (1.6-fold higher than that of rose bengal in CH₃CN) and highly specific ER localization ability, which demonstrated the promise of the metal-based photo-theranostic agent by simultaneously tuning the photochemical/physical and biological properties. Additionally, low dark cytotoxicity, high photostability and selective tumour cell uptake were featured by this complex to demonstrate it as a promising candidate in photodynamic therapy (PDT) applications. In vivo near infrared fluorescence (NIRF) imaging and tumour PDT were investigated and showed preferential accumulation at the tumour site and remarkable tumour growth suppression, respectively.