Carbon–Dipyrromethenes: Bright Cationic Fluorescent Dyes and Potential Application in Revealing Cellular Trafficking of Mitochondrial Glutathione Conjugates

Abstract

Boron−dipyrromethenes (Bodipys), since first reported in 1968, have emerged as a fascinating class of dyes in the past few decades due to their excellent photophysical properties including bright fluorescence, narrow emission bandwidth, resistance to photobleaching, and environment insensitivity. However, typical Bodipys are highly lipophilic, which often results in nonfluorescent aggregates in aqueous solution and also severely limits their bioavailability to cells and tissues. In this work, based on a simple one-atom B → C replacement in the Bodipy scaffold, we present a new class of carbon−dipyrromethenes (Cardipys for short) fluorescent dyes with tunable emission wavelengths covering the visible and nearinfrared regions. These Cardipys not only retain the excellent photophysical properties of conventional Bodipys but also show improved water solubility and photostability due to their cationic character. Moreover, the cationic character also makes them extremely easy to penetrate the cell membrane and specifically accumulate into mitochondria without resorting to any mitochondriatargeted groups. Interestingly, several Cardipys bearing active styryl groups could serve as fluorescent indicators to map cellular trafficking of the glutathione conjugates produced within mitochondria under the catalysis of glutathione S-transferase (GST), thus showing potential in either exploring the detoxification mechanism of the mitochondrial GST/GSH system or evaluating the drug resistance of cancer cells that is closely related with GST activity.

Near-infrared dyes for two-photon absorption in the short-wavelength infrared: strategies towards optical power limiting

“…44), 156,159,[162][163][164][165] rigidification of the conjugated backbone by annelation, 166 167 or replacement the boron centre by a carbon atom, in recently disclosed cardipy dyes. 168 According to theoretical predictions, the combination of these approaches would lead to highly red-shifted absorptions, up to ca. 1000 nm for the most optimized structures.…”

Aggregation Turns BODIPY Fluorophores into Photosensitizers: Reversibly Switching Intersystem Crossing On and Off for Smart Photodynamic Therapy

“…Organic fluorophores are widely used in many areas such as fluorescent probes [1][2][3][4][5][6] , bioimaging [7][8][9][10][11] and organic light emitting diodes [12][13][14] . Normally, exciting a fluorophore in dilute solution generates a lowest singlet excited state (S 1 ), which rapidly relaxes back to the ground state (S 0 ) through emitting fluorescence.…”

Photodynamic therapy applications of Re(I)‐BODIPY functionalized nanoparticles

“…It is clear from the images that most of the NP's surrounded the cell nuclei, which suggest cytoplasmic localization. [ 37,38 ] Additionally, these findings revealed that the NPReL induced the changes broadly in cytoplasmic skeleton and nuclei, therefore causes the cytotoxicity to the c6 cancer cells. Furthermore, quantified uptake or association of NPReL with cells and the accurate quantification of rhenium content was analyzed by ICP‐MS.…”