Naphthalene-fused BODIPY near-infrared dye as a stable contrast agent for in vivo photoacoustic imaging

Abstract

Photoacoustic imaging (PAI) has emerged as an advantageous modality with high resolution and deep tissue penetration. However, its application is limited by the lack of available contrast agents. In this work, we report the synthesis of a naphthalene fused BODIPY dimer Na-BD, and the impact of the electronic structure on the oxidative cyclo-dehydrogenation process was systematically studied. Na-BD exhibited intense NIR absorption, much better photo-stability and higher PA activity compared to commercial ICG dye, which makes it an excellent contrast agent for PAI. Moreover, the in vivo PAI studies based on Na-BD loaded BSA nanoparticles were carried out and they demonstrated a significant passive targeting capacity by exploiting the enhanced permeability and retention effect in the tumor region.

Strategies for Preparing Albumin-based Nanoparticles for Multifunctional Bioimaging and Drug Delivery

“…The prepared albumin-based nanoparticles could be used for chemotherapy, PTT, PDT, combinational therapy, optical imaging, MRI, photoacoustic tomography, multimodal imaging or theranostics 80 - 84 . In comparison with small molecular drug formulations, albumin-based nanoparticles perform special functions, such as the efficient treatment of drug-resistant and orthotopic brain tumors 81 , 85 - 87 . Systematic study on albumin-based nanomedicine shows not only tumor targeted drug delivery but also alleviated in vivo drug toxicity 88 .…”

“…SPARC and gp60) are overexpressed in many tumors; however, further conjugation of targeted ligand to albumin-based nanoparticles could increase specific nanoparticle uptake into cancer cells 86 , 89 - 92 . The utilized targeted ligands could be a nanobody, FA, peptide, glycyrrhetinic acid, antibody, mannose and TNF-related apoptosis-inducing ligand (TRAIL) 87 , 92 - 98 . Dual modifications with a targeted peptide and cell-penetrating peptide could improve the tumor targeting and cell penetration of nanoparticles 95 .…”

“…Our group found that the squaraine dye loaded into an albumin-based nanoparticle would result in absorption spectrum red-shift to the NIR range; this phenomenon quenched the fluorescence, but benefited the NIR photoacoustic tomography 128 . A newly synthesized naphthalene-fused Bodipy dye showed strong absorption beyond 700 nm wavelength and was a stable contrast agent for in vivo photoacoustic tomography 87 . Loading with pH-responsive dye could be used for intracellular pH mapping 129 .…”

Current concepts in nanostructured contrast media development for in vivo photoacoustic imaging

“…32,33 In addition, other dyes such as Prussian blue, Coomassie blue, BODIPYs (4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes), porphyrines and cyanines have been explored for the purpose, showing good contrasts and sensing behaviour in vivo. 34,35,[36][37][38][39][40][41][42][43]44 However, the development of new small molecule dyes as contrast agents for preclinical PA imaging is strongly limited by their molecular properties: the high conjugation degree required for NIR absorption drastically decreases the water-dispersibility properties of the dyes, leading to low stability in aqueous media and concentration-dependent optical properties. Moreover, no SMD capable of interacting with light waves longer than 800 nm has been reported, and their optical absorption coefficient is still quite low (<5000 M −1 cm −1 ) compared to most nanostructured photoabsorbers.…”

Near-infrared fluorescent and columnar liquid crystal: synthesis, and photophysical and mesomorphic properties of triphenylene-Bodipy-triphenylene triad

“…13 On the other hand, Bodipy had been applied as a good platform to construct near-infrared materials by extending its aromatic conjugated system. [35][36][37][38][39][40] Therefore, it can be question whether it is possible to design and synthesize the columnar Bodipy liquid crystal with near-infrared uorescence. This type of nearinfrared columnar liquid crystal has not thus far been reported.…”