Fluorescent BODIPY-Anionic Boron Cluster Conjugates as Potential Agents for Cell Tracking

Abstract

A series of novel fluorescent BODIPY-anionic boron cluster conjugates bearing [BH] (5, 6), [3,3'-Co(1,2-CBH)] (7, 8), and [3,3'-Fe(1,2-CBH)] (9) anions have been readily synthesized from meso-(4-hydroxyphenyl)-4,4-difluoro-4-bora-3 a,4 a-diaza- s-indacene (BODIPY 4), and their structure and photoluminescence properties have been assessed. Linking anionic boron clusters to the BODIPY (4) does not alter significantly the luminescent properties of the final fluorophores, showing all of them similar emission fluorescent quantum yields (3-6%). Moreover, the cytotoxicity and cellular uptake of compounds 5-9 have been analyzed in vitro at different concentrations of B (5, 50, and 100 μg B/mL) using HeLa cells. At the lowest concentration, none of the compounds shows cytotoxicity and they are successfully internalized by the cells, especially compounds 7 and 8, which exhibit a strong cytoplasmic stain indicating an excellent internalization efficiency. To the best of our knowledge, these are the first BODIPY-anionic boron cluster conjugates developed as fluorescent dyes aiming at prospective biomedical applications. Furthermore, the cellular permeability of the starting BODIPY (4) was improved after the functionalization with boron clusters. The exceptional cellular uptake and intracellular boron release, together with the fluorescent and biocompatibility properties, make compounds 7 and 8 good candidates for in vitro cell tracking.

Photoluminescence in m-carborane–anthracene triads: a combined experimental and computational study

“…[19][20][21] . Owing to the intrinsic properties of carboranes, they have been used as exceptional building blocks for developing functional organic materials with enhanced thermal and chemical properties 22-25 . In the last decade, the development of boron cluster-based organic -conjugated systems have attracted huge interest as active materials in (opto)electronic devices, such as organic lightemitting diodes (OLEDs), organic field effect transistors (OFETs), solar cells, biological sensors and imaging, [26][27][28] among others. 29,30 It has been demonstrated the remarkable influence of the o-carborane cluster on the photophysical properties of luminescent materials in solution and solid state.…”

Blue Emitting Star-Shaped and Octasilsesquioxane-Based Polyanions Bearing Boron Clusters. Photophysical and Thermal Properties

“…Decoration of the star-shaped core 1,3,5-Tris(4-hydroxyphenyl)benzene (1) with the anionic boron clusters was performed via nucleophilic ring-opening reaction of their oxonium-derivatives [92], i.e., [Bu4N][B12H11(C4H8O2)] (2) and [3,3′-Co(8-C4H8O2-1,2-C2B9H10)(1′,2′-C2B9H11)] (3) [93,94]. Compound 4 was prepared following previously described conditions [95][96][97][98][99][100]: Firstly, deprotonation of hydroxy groups in 1 with K2CO3 takes place, and secondly, phenoxy moieties undergo a nucleophilic attack promoting the ring-opening reaction of 2. In a similar manner, compound 5 was synthesised from 1 and COSAN derivative 3 using NaH as a deprotonating agent.…”

Efficient blue light emitting materials based on m-carborane–anthracene dyads. Structure, photophysics and bioimaging studies

“…This means that the compounds may increase the metabolic activity of the cells, but not their proliferation, or generate some kind of interference with the Alamar Blue technique, as has already been reported with both resazurin and MTT assays. 27,28 Cell internalization of the compounds was assessed by confocal microscopy. Although the laser used was in the limit of the compound absorption range (300-400 nm), all compounds were successfully detected inside the cells, showing a fluorescence spotted pattern in the cytosol (Fig.…”