DMAP‐BODIPY Alkynes: A Convenient Tool for Labeling Biomolecules for Bimodal PET–Optical Imaging

Abstract

Several new boron dipyrromethene/N,N-dimethylaminopyridine (BODIPY-DMAP) assemblies were synthesized as precursors for bimodal imaging probes (optical imaging, OI/positron emission tomography, PET). The photophysical properties of the new compounds were also studied. The first proof-of-concept was obtained with the preparation of several new BODIPY-labeled bombesins and evaluation of the affinity for bombesin receptors by using a competition binding assay. Fluorination reactions were investigated on DMAP-BODIPY precursors as well as on DMAP-BODIPY-labeled bombesins. Chemical modifications on the BODIPY core were also performed to obtain luminescent dyes emitting in the therapeutic window (650-900 nm), suitable for in vivo imaging, making these compounds promising precursors for PET/optical dual-modality imaging agents.

Porphyrinoid biohybrid materials as an emerging toolbox for biomedical light management

“…Many functional peptide libraries have actually been described in the literature, with different sequences and functions, offering a versatile platform of delivery agents to localize PS conjugates in different kinds of cells and tissues. 48 Covalently linked PS-peptide biohybrids can be synthesized, taking advantage of mild synthetic organic methodologies such as amide [49][50][51][52][53]77,78,81,[85][86][87]89,[91][92][93]95,97,104,105 or sulphonamide 54 bond formation, palladium-catalysed cross-coupling reactions, 55,56 click-chemistry reactions [57][58][59]81,94 and isothiocyanate chemistry, 60,82 among other strategies. Supramolecular approaches have also been used toward self-assembled peptide nanofibers, 61 nanodots, 62 vesicles, 63 light harvesting complexes, 64 arrays 65 or polymeric micelles with a peptide-decorated surface, 66 among others.…”

“…Besides, bombesin has been linked to a BODIPY in experiments carried out by Brizet et al, the resulting hybrid being suitable for bimodal PET/optical imaging. 82 The a v b 3 integrin, on the other hand, is a protein present in many tumour cells, which is implicated in different tumoral processes such as tumour growth, angiogenesis and metastasis. This protein is expressed in tumour endothelial cells, and it can be recognized by the RGD triad.…”

Towards the elaboration of new gold-based optical theranostics

“…A cysteine residue was finally added to enable the coupling reaction of the gold atom via the thiol group of the lateral chain. The BBN-SH peptide (Cys-AEEAc-bombesin (7)(8)(9)(10)(11)(12)(13)(14) ) was obtained by automated solid phase peptide synthesis on a microwave synthesizer. The synthesis was carried out on a Rink Amide AM resin.…”

Fluorine-18-Labeled Fluorescent Dyes for Dual-Mode Molecular Imaging

“…In 2014, Brizet et al used the BODIPY-DMAP stability to synthesize a series of PET imaging precursors [66]. They showed that the DMAP adduct withstands Huisgen cycloaddition conditions, isothiocyanate synthesis, and their subsequent coupling with amines.…”