A photoactive Ir-Pd bimetallic cage with high singlet oxygen yield for efficient one/two-photon activated photodynamic therapy

• Published in: Materials chemistry frontiers Vol. 6; no. 7; pp. 948 - 955
• Main Authors: Liu, Yuan-Yuan, Yu, Hui-Juan, Wang, Ya-Ping, Li, Chao-Jie, Wang, Xiao-Fei, Ye, Cai-Guo, Yao, Hong-Liang, Pan, Mei, Su, Cheng-Yong
• Format: Journal Article
• Language: English
• Published: London Royal Society of Chemistry 28.03.2022
• Subjects: Apoptosis; Bimetals; Cages; Cancer; Excitation; Mitochondria; Penetration depth; Photodynamic therapy; Photons; Singlet oxygen; Tumors
• ISSN: 2052-1537; 2052-1537
• DOI: 10.1039/d1qm01578h

Photodynamic therapy (PDT) has been extensively studied as a noninvasive treatment option; however, the current PDT agents are often restricted with poor solubility, difficult accumulation in tumor sites, low singlet oxygen yield and low penetration depth. Herein we develop a one-/two-photon excitation [Pd 4 Ir 8 ] 16+ supramolecular cage (MOC-53) comprising multiple Ir( iii ) metalloligands, which can be quickly taken up by cancer cells to locate in the mitochondria with an ultra-high singlet oxygen generation efficiency (0.84). In particular, MOC-53 also exhibits singlet oxygen generation capability under two-photon excitation to enhance the depth of penetration and reduce photo-damage. JC-1 assays, Annexin V-FITC/PI assays and the activity of caspase-3/7 analyses show that MOC-53 can activate apoptosis efficiently. The tumor volume growth of mice after the intra-tumoral injection of MOC-53 is obviously restrained under the two-photon irradiation, showing a potential opportunity for photodynamic cancer treatment. Photodynamic therapy (PDT) has been extensively studied as a noninvasive treatment option; however, the current PDT agents are often restricted with poor solubility, difficult accumulation in tumor sites, low singlet oxygen yield and low penetration depth.