title: Iridium(III) Anthraquinone Complexes as Two-Photon Phosphorescence Probes for Mitochondria Imaging and Tracking under Hypoxia.
abstract: In the present study, four mitochondria-specific and two-photon phosphorescence iridium(III) complexes, Ir1-Ir4, were developed for mitochondria imaging in hypoxic tumor cells. The iridium(III) complex has two anthraquinone groups that are hypoxia-sensitive moieties. The phosphorescence of the iridium(III) complex was quenched by the functions of the intramolecular quinone unit, and it was restored through two-electron bioreduction under hypoxia. When the probes were reduced by reductase to hydroquinone derivative products under hypoxia, a significant enhancement in phosphorescence intensity was observed under one- (λ=405 nm) and two-photon (λ=720 nm) excitation, with a two-photon absorption cross section of 76-153 GM at λ=720 nm. More importantly, these probes possessed excellent specificity for mitochondria, which allowed imaging and tracking of the mitochondrial morphological changes in a hypoxic environment over a long period of time. Moreover, the probes can visualize hypoxic mitochondria in 3D multicellular spheroids and living zebrafish through two-photon phosphorescence imaging.
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Sun
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China.
authors.forename: Shi
authors.initials: S
authors.lastname: Kuang
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China.
authors.forename: Guanying
authors.initials: G
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China.
authors.forename: Ruilin
authors.initials: R
authors.lastname: Guan
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China.
authors.forename: Jiangping
authors.initials: J
authors.lastname: Liu
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China.
authors.forename: Liangnian
authors.initials: L
authors.lastname: Ji
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, P.R. China. ceschh@mail.sysu.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Chao
mesh_terms: D000072283:A549 Cells; D000818:Animals; D000880:Anthraquinones / Q000737:chemistry*; D001921:Brain / Q000378:metabolism / Q000473:pathology; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D056831:Coordination Complexes / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D006801:Humans; D006863:Hydrogen-Ion Concentration; D021621:Imaging, Three-Dimensional; D007495:Iridium / Q000737:chemistry*; D013058:Mass Spectrometry; D018613:Microscopy, Confocal; D036641:Microscopy, Fluorescence, Multiphoton; D008862:Microsomes, Liver / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D013050:Spectrometry, Fluorescence; D018874:Spheroids, Cellular / Q000166:cytology / Q000378:metabolism; D015027:Zebrafish / Q000378:metabolism
chemical_list: D000880:Anthraquinones; D056831:Coordination Complexes; D007495:Iridium
keywords: biological activity; hypoxia; imaging agents; iridium; photochemistry