Enhanced in vivo Optical Imaging of the Inflammatory Response to Acute Liver Injury in C57BL/6 Mice Using a Highly Bright Near‐Infrared BODIPY Dye

Abstract

Delving deeper is possible in whole‐body in vivo imaging using a super‐bright membrane‐targeting BODIPY dye (BD). The dye was used to monitor homing of ex vivo fluorescently labelled neutrophils to an injured liver of dark‐pigmented C57BL/6 mice. In vivo imaging system (IVIS) data conclusively showed an enhanced signal intensity and a higher signal‐to‐noise ratio in mice receiving neutrophils labelled with the BD dye relative to those labelled with a gold standard dye at 2 h post in vivo administration of fluorescently labelled cells. Fluorescence‐activated cell sorting (FACS) confirmed that BD is nontoxic, and an exceptional cell labelling dye that opens up precision deep‐organ in vivo imaging of inflammation in mice routinely used for biomedical research. The origin of enhanced performance is identified with the molecular structure and the distinct localisation of the dye within cells that enable remarkable changes in its optical parameters.

Pd and Pt Complexes of Benzo-Fused Dipyrrins: Synthesis, Structure, Electrochemical, and Optical Properties

“…Among the four states, one with a ″pure″ LC transition (HOMO−1 → LUMO+1, S4) and one with a ligand-to-metal charge-transfer (LMCT) transition (HOMO → LUMO, S1 or 1 LMCT 1 ) are symmetry-forbidden. We call these two states (S1 and S4) 1 LMCT 1 and 1 LC 2 , respectively.…”

“…For the Pd(L) 2 complex, the initial photoexcitation at the main transition band can populate both the 1 LMCT and 1 LC 1 states, which decay very quickly via internal conversion to form the spin-allowed LMCT state ( 1 LMCT 1 ). 1 LMCT 1 then undergoes ISC to form the low-energy triplet excited state ( 3 LMCT). The rate of ISC in the Pd(L) 2 complex (∼9 ps) is comparable to other Pd 2+ complexes reported.…”

“…Owing to their rich and diverse coordination chemistry, they form complexes with a variety of metal ions. The most popular and stable complex of dipyrrin with boron difluoride, known as BODIPY, is widely used as a fluorophore for biomedical applications, such as imaging, − sensing, − and photodynamic therapy. − On the other hand, dipyrrin complexes with transition metals can be advantageous for catalysis, , the preparation of coordination polymers, − metal–organic frameworks, − and self-assembly of supramolecules − due to the facile complexation reactions.…”

Non-invasive synchronous monitoring of neutrophil migration using whole body near-infrared fluorescence-based imaging

“…Positron-Emission Tomography (PET) and Single-Photon Emission Tomography (SPECT) use ionising radiation as a cell marker, whilst, Magnetic Resonance Imaging (MRI) exploits contrast agents that produce a magnetic spin to visualise cells in a small animal 3 . Unlike MRI and PET/SPECT, optical imaging detects photons emitted from fluorophores that have distinct spectral signatures 4 . Therefore, in vivo fluorescence imaging modalities, theoretically could facilitate synchronous multiplex imaging of various probes with different spectral properties.…”