Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia Imaging
In this work, we obtained three new phosphorescent iridium complexes (<b>Ir1</b>–<b>Ir3</b>) of general stoichiometry [Ir(N^C)<sub>2</sub>(N^N)]Cl decorated with oligo(ethylene glycol) fragments to make them water-soluble and biocompatible, as well as to protect t...
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MDPI AG
2023-06-01
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| Series: | Biosensors |
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| Online Access: | https://www.mdpi.com/2079-6374/13/7/680 |
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| author | Mozhgan Samandarsangari Daria O. Kozina Victor V. Sokolov Anastasia D. Komarova Marina V. Shirmanova Ilya S. Kritchenkov Sergey P. Tunik |
| author_facet | Mozhgan Samandarsangari Daria O. Kozina Victor V. Sokolov Anastasia D. Komarova Marina V. Shirmanova Ilya S. Kritchenkov Sergey P. Tunik |
| author_sort | Mozhgan Samandarsangari |
| collection | DOAJ |
| description | In this work, we obtained three new phosphorescent iridium complexes (<b>Ir1</b>–<b>Ir3</b>) of general stoichiometry [Ir(N^C)<sub>2</sub>(N^N)]Cl decorated with oligo(ethylene glycol) fragments to make them water-soluble and biocompatible, as well as to protect them from aggregation with biomolecules such as albumin. The major photophysical characteristics of these phosphorescent complexes are determined by the nature of two cyclometallating ligands (N^C) based on 2-pyridine-benzothiophene, since quantum chemical calculations revealed that the electronic transitions responsible for the excitation and emission are localized mainly at these fragments. However, the use of various diimine ligands (N^N) proved to affect the quantum yield of phosphorescence and allowed for changing the complexes’ sensitivity to oxygen, due to the variations in the steric accessibility of the chromophore center for O<sub>2</sub> molecules. It was also found that the N^N ligands made it possible to tune the biocompatibility of the resulting compounds. The wavelengths of the <b>Ir1</b>–<b>Ir3</b> emission maxima fell in the range of 630–650 nm, the quantum yields reached 17% (<b>Ir1</b>) in a deaerated solution, and sensitivity to molecular oxygen, estimated as the ratio of emission lifetime in deaerated and aerated water solutions, displayed the highest value, 8.2, for <b>Ir1</b>. The obtained complexes featured low toxicity, good water solubility and the absence of a significant effect of biological environment components on the parameters of their emission. Of the studied compounds, <b>Ir1</b> and <b>Ir2</b> were chosen for in vitro and in vivo biological experiments to estimate oxygen concentration in cell lines and tumors. These sensors have demonstrated their effectiveness for mapping the distribution of oxygen and for monitoring hypoxia in the biological objects studied. |
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| language | English |
| last_indexed | 2024-03-11T01:15:37Z |
| publishDate | 2023-06-01 |
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| spelling | doaj.art-666f5df7428e473eb429bb5cfc8eb0642023-11-18T18:32:28ZengMDPI AGBiosensors2079-63742023-06-0113768010.3390/bios13070680Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia ImagingMozhgan Samandarsangari0Daria O. Kozina1Victor V. Sokolov2Anastasia D. Komarova3Marina V. Shirmanova4Ilya S. Kritchenkov5Sergey P. Tunik6Institute of Chemistry, St. Petersburg State University, Universitetskaya Embankment 7-9, 199034 St. Petersburg, RussiaInstitute of Chemistry, St. Petersburg State University, Universitetskaya Embankment 7-9, 199034 St. Petersburg, RussiaInstitute of Chemistry, St. Petersburg State University, Universitetskaya Embankment 7-9, 199034 St. Petersburg, RussiaInstitute of Experimental Oncology and Biomedical Technologies, Privolzhskiy Research Medical University, Minin and Pozharsky Sq. 10/1, 603005 Nizhny Novgorod, RussiaInstitute of Experimental Oncology and Biomedical Technologies, Privolzhskiy Research Medical University, Minin and Pozharsky Sq. 10/1, 603005 Nizhny Novgorod, RussiaInstitute of Chemistry, St. Petersburg State University, Universitetskaya Embankment 7-9, 199034 St. Petersburg, RussiaInstitute of Chemistry, St. Petersburg State University, Universitetskaya Embankment 7-9, 199034 St. Petersburg, RussiaIn this work, we obtained three new phosphorescent iridium complexes (<b>Ir1</b>–<b>Ir3</b>) of general stoichiometry [Ir(N^C)<sub>2</sub>(N^N)]Cl decorated with oligo(ethylene glycol) fragments to make them water-soluble and biocompatible, as well as to protect them from aggregation with biomolecules such as albumin. The major photophysical characteristics of these phosphorescent complexes are determined by the nature of two cyclometallating ligands (N^C) based on 2-pyridine-benzothiophene, since quantum chemical calculations revealed that the electronic transitions responsible for the excitation and emission are localized mainly at these fragments. However, the use of various diimine ligands (N^N) proved to affect the quantum yield of phosphorescence and allowed for changing the complexes’ sensitivity to oxygen, due to the variations in the steric accessibility of the chromophore center for O<sub>2</sub> molecules. It was also found that the N^N ligands made it possible to tune the biocompatibility of the resulting compounds. The wavelengths of the <b>Ir1</b>–<b>Ir3</b> emission maxima fell in the range of 630–650 nm, the quantum yields reached 17% (<b>Ir1</b>) in a deaerated solution, and sensitivity to molecular oxygen, estimated as the ratio of emission lifetime in deaerated and aerated water solutions, displayed the highest value, 8.2, for <b>Ir1</b>. The obtained complexes featured low toxicity, good water solubility and the absence of a significant effect of biological environment components on the parameters of their emission. Of the studied compounds, <b>Ir1</b> and <b>Ir2</b> were chosen for in vitro and in vivo biological experiments to estimate oxygen concentration in cell lines and tumors. These sensors have demonstrated their effectiveness for mapping the distribution of oxygen and for monitoring hypoxia in the biological objects studied.https://www.mdpi.com/2079-6374/13/7/680oxygen sensingiridium complexesphosphorescencehypoxiabioimagingphosphorescence lifetime imaging |
| spellingShingle | Mozhgan Samandarsangari Daria O. Kozina Victor V. Sokolov Anastasia D. Komarova Marina V. Shirmanova Ilya S. Kritchenkov Sergey P. Tunik Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia Imaging Biosensors oxygen sensing iridium complexes phosphorescence hypoxia bioimaging phosphorescence lifetime imaging |
| title | Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia Imaging |
| title_full | Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia Imaging |
| title_fullStr | Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia Imaging |
| title_full_unstemmed | Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia Imaging |
| title_short | Biocompatible Phosphorescent O<sub>2</sub> Sensors Based on Ir(III) Complexes for In Vivo Hypoxia Imaging |
| title_sort | biocompatible phosphorescent o sub 2 sub sensors based on ir iii complexes for in vivo hypoxia imaging |
| topic | oxygen sensing iridium complexes phosphorescence hypoxia bioimaging phosphorescence lifetime imaging |
| url | https://www.mdpi.com/2079-6374/13/7/680 |
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