Lower Energy Excitation of Water Soluble Near-Infrared Emitting Mixed-Ligand Metallacrowns.

By combining advantages of two series of lanthanide(III)/zinc(II) metallacrowns (MCs) assembled using pyrazine- (pyzHA ) and quinoxaline- (quinoHA ) hydroximate building blocks ligands, we created here water-soluble mixed-ligand MCs with extended absorption to the visible range. The Yb analogue demonstrated improved photophysical properties in the near-infrared (NIR) range in cell culture media, facilitating its application for NIR optical imaging in living HeLa cells.

Pyridazino-1,3a,6a-Triazapentalenes as Versatile Fluorescent Probes: Impact of Their Post-Functionalization and Application for Cellular Imaging.

Pyridazino-1,3a,6a-triazapentalenes (PyTAP) are compact fused 6/5/5 tricyclic scaffolds which exhibit promising fluorescent properties. Chemically stable, they can be post-functionalized using standard Pd-catalyzed cross-coupling chemistry. Several original PyTAP bearing additional unsaturated substituents in positions 2 and 8 were synthetized and their spectroscopic properties analyzed.

Iodinated Metallacrowns: Toward Combined Bimodal Near-Infrared and X-Ray Contrast Imaging Agents.

Multimodal probes capable of combining imaging modalities within a single molecule are in high demand today as they can provide information at both molecular and anatomical levels. Herein, a study was conducted on a series of gallium(III)/lanthanide(III) bis(12-MC-4) metallacrowns (MCs) with the general composition {Ln[12-MC -4]} (iph) (Ln-I , x=0, 4, 8, 12), where shi and iph are salicylhydroximate and isophthalate ligands, respectively, or their iodinated derivatives. For Yb-I , the attenuation in X-ray computed tomography (XCT) imaging and near-infrared (NIR) luminescence properties can be finely tuned by controlled structural modifications based on iodo groups.

An original class of small sized molecules as versatile fluorescent probes for cellular imaging.

An unusual class, compact in size, of fluorescent probes based on pyridazino-1,3a,6a-triazapentalene scaffolds exhibits promising fluorescent properties (quantum yield values up to 73%, large Stokes shifts, emission wavelengths located in the green-yellow range, excellent solubility) with good photostability suitable for optical imaging applications.

One Approach for Two: Toward the Creation of Near-Infrared Imaging Agents and Rapid Screening of Lanthanide(III) Ion Sensitizers Using Polystyrene Nanobeads.

The unique luminescence properties of lanthanide(III) ions (Ln) in the near-infrared (NIR) range are attracting major attention in view of their exciting applications in the fields of technology, telecommunications, biology, and medicine. One of the main strategies to design luminescent Ln-based compounds relies on their sensitization through appropriate chromophoric ligands. The choice of the chromophores depends on the nature of Ln and, as of today, still partially requires experimental trials, in particular, for the creation of luminescent compounds incorporating NIR-emitting Ln.

Engineered immune cells as highly sensitive cancer diagnostics.

Endogenous biomarkers remain at the forefront of early disease detection efforts, but many lack the sensitivities and specificities necessary to influence disease management. Here, we describe a cell-based in vivo sensor for highly sensitive early cancer detection. We engineer macrophages to produce a synthetic reporter on adopting an M2 tumor-associated metabolic profile by coupling luciferase expression to activation of the arginase-1 promoter.

Near-infrared luminescent metallacrowns for combined cell fixation and counter staining.

Cell fixation is an essential approach for preserving cell morphology, allowing the targeting and labelling of biomolecules with fluorescent probes. One of the key requirements for more efficient fluorescent labelling is the preservation of cell morphology, which usually requires a combination of several fixation techniques. In addition, the use of a counter stain is often essential to improve the contrast of the fluorescent probes.

One-Step Assembly of Visible and Near-Infrared Emitting Metallacrown Dimers Using a Bifunctional Linker.

A family of dimeric Ln [12-MC -4] metallacrowns (MCs) (Ln =Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) was synthesized using the isophthalate group (ip ) as a linker. The [LnGa ] complexes exhibit remarkable photophysical properties, with large molar absorptivities of ≈4×10  m  cm , high quantum yields and long luminescence lifetimes with values of (i) 31.2(2)% and 1.

Near-Infrared Optical Imaging of Necrotic Cells by Photostable Lanthanide-Based Metallacrowns.

Sensitive detection of cell necrosis is crucial for the determination of cell viability. Because of its high resolution at the cellular level and sensitivity, optical imaging is highly attractive for identifying cell necrosis. However, challenges associated with this technique remain present such as the rapid photobleaching of several types of organic fluorophores and/or the interference generated by biological autofluorescence.