ExTzBox

A Glowing Cyclophane for Live-Cell Imaging

Indranil Roy, Sharan Bobbala, Jiawang Zhou, Minh T. Nguyen, Siva Krishna Mohan Nalluri, Yilei Wu, Daniel P. Ferris, Evan Alexander Scott, Michael R Wasielewski, J. Fraser Stoddart

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The ideal fluorescent probe for live-cell imaging is bright and non-cytotoxic and can be delivered easily into the living cells in an efficient manner. The design of synthetic fluorophores having all three of these properties, however, has proved to be challenging. Here, we introduce a simple, yet effective, strategy based on well-established chemistry for designing a new class of fluorescent probes for live-cell imaging. A box-like hybrid cyclophane, namely ExTzBox·4X (6·4X, X = PF6-, Cl-), has been synthesized by connecting an extended viologen (ExBIPY) and a dipyridyl thiazolothiazole (TzBIPY) unit in an end-to-end fashion with two p-xylylene linkers. Photophysical studies show that 6·4Cl has a quantum yield φF = 1.00. Furthermore, unlike its ExBIPY2+ and TzBIPY2+ building units, 6·4Cl is non-cytotoxic to RAW 264.7 macrophages, even with a loading concentration as high as 100 μM, presumably on account of its rigid box-like structure which prevents its intercalation into DNA and may inhibit other interactions with it. After gaining an understanding of the toxicity profile of 6·4Cl, we employed it in live-cell imaging. Confocal microscopy has demonstrated that 64+ is taken up by the RAW 264.7 macrophages, allowing the cells to glow brightly with blue laser excitation, without any hint of photobleaching or disruption of normal cell behavior under the imaging conditions. By contrast, the acyclic reference compound Me2TzBIPY·2Cl (4·2Cl) shows very little fluorescence inside the cells, which is quenched completely under the same imaging conditions. In vitro cell investigations underscore the significance of using highly fluorescent box-like rigid cyclophanes for live-cell imaging.

Original languageEnglish
Pages (from-to)7206-7212
Number of pages7
JournalJournal of the American Chemical Society
Volume140
Issue number23
DOIs
Publication statusPublished - Jun 13 2018

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Imaging techniques
Macrophages
Fluorescent Dyes
Viologens
Photobleaching
Laser excitation
Fluorophores
Confocal microscopy
Quantum yield
Intercalation
Toxicity
DNA
Fluorescence
Cells
Confocal Microscopy
Lasers

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Roy, I., Bobbala, S., Zhou, J., Nguyen, M. T., Nalluri, S. K. M., Wu, Y., ... Stoddart, J. F. (2018). ExTzBox: A Glowing Cyclophane for Live-Cell Imaging. Journal of the American Chemical Society, 140(23), 7206-7212. https://doi.org/10.1021/jacs.8b03066

ExTzBox : A Glowing Cyclophane for Live-Cell Imaging. / Roy, Indranil; Bobbala, Sharan; Zhou, Jiawang; Nguyen, Minh T.; Nalluri, Siva Krishna Mohan; Wu, Yilei; Ferris, Daniel P.; Scott, Evan Alexander; Wasielewski, Michael R; Stoddart, J. Fraser.

In: Journal of the American Chemical Society, Vol. 140, No. 23, 13.06.2018, p. 7206-7212.

Research output: Contribution to journalArticle

Roy, I, Bobbala, S, Zhou, J, Nguyen, MT, Nalluri, SKM, Wu, Y, Ferris, DP, Scott, EA, Wasielewski, MR & Stoddart, JF 2018, 'ExTzBox: A Glowing Cyclophane for Live-Cell Imaging', Journal of the American Chemical Society, vol. 140, no. 23, pp. 7206-7212. https://doi.org/10.1021/jacs.8b03066
Roy I, Bobbala S, Zhou J, Nguyen MT, Nalluri SKM, Wu Y et al. ExTzBox: A Glowing Cyclophane for Live-Cell Imaging. Journal of the American Chemical Society. 2018 Jun 13;140(23):7206-7212. https://doi.org/10.1021/jacs.8b03066
Roy, Indranil ; Bobbala, Sharan ; Zhou, Jiawang ; Nguyen, Minh T. ; Nalluri, Siva Krishna Mohan ; Wu, Yilei ; Ferris, Daniel P. ; Scott, Evan Alexander ; Wasielewski, Michael R ; Stoddart, J. Fraser. / ExTzBox : A Glowing Cyclophane for Live-Cell Imaging. In: Journal of the American Chemical Society. 2018 ; Vol. 140, No. 23. pp. 7206-7212.
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