title: Cyclometalated Iridium(III) Complexes as Two-Photon Phosphorescent Probes for Specific Mitochondrial Dynamics Tracking in Living Cells.
abstract: Five cyclometalated iridium(III) complexes with 2-phenylimidazo[4,5-f][1,10]phenanthroline derivatives (IrL1-IrL5) were synthesized and developed to image and track mitochondria in living cells under two-photon (750 nm) excitation, with two-photon absorption cross-sections of 48.8-65.5 GM at 750 nm. Confocal microscopy and inductive coupled plasma-mass spectrometry (ICP-MS) demonstrated that these complexes selectively accumulate in mitochondria within 5 min, without needing additional reagents for membrane permeabilization, or replacement of the culture medium. In addition, photobleaching experiments and luminescence measurements confirmed the photostability of these complexes under continuous laser irradiation and physiological pH resistance. Moreover, results using 3D multicellular spheroids demonstrate the proficiency of these two-photon luminescent complexes in deep penetration imaging. Two-photon excitation using such novel complexes of iridium(III) for exclusive visualization of mitochondria in living cells may substantially enhance practical applications of bioimaging and tracking.
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: Chengzhi
authors.initials: C
authors.lastname: Jin
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: 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: Leli
authors.initials: L
authors.lastname: Zeng
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: Cheng
authors.initials: C
authors.lastname: Ouyang
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: D006367:HeLa Cells; D006801:Humans; D007495:Iridium / Q000737:chemistry*; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods; D013058:Mass Spectrometry; D063154:Mitochondrial Dynamics / Q000187:drug effects*; D009942:Organometallic Compounds / Q000737:chemistry*; D017785:Photons
chemical_list: D049408:Luminescent Agents; D009942:Organometallic Compounds; D007495:Iridium
keywords: cyclometalation; imaging agents; iridium; mitochondrial tracking; two-photon excitation