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A new near-infrared (NIR)-emitting aza-boron-dipyrromethene dye with two electron-donating amino groups at 1- and 7-positions has been prepared via several steps of reactions. This probe showed a NIR absorption at 748 nm with an obvious shoulder peak at 634 nm in CH 3 CN/H 2 O. Interestingly, a NIR fluorescence emission at 843 nm was observed with a large Stokes shift of 95 nm. This novel NIR-emitting aza-boron-dipyrromethene dye was further investigated as a Hg 2+ -sensing fluorescent probe, which selectively bound to Hg 2+ , showing a blue-shifted and sharp absorption band at 695 nm with the disappearance of the shoulder peak at 634 nm. Correspondingly, the color change could be easily seen from blue to green. Interestingly, the emission exhibited an absolutely "turn-on" peak at 725 nm with a significant blue shift by 118 nm (from 843 to 725 nm), due to the efficient inhibition of the intramolecular-charge-transfer process arising from two amino groups. This probe was finally introduced to Hela cells, showing a "OFF-ON" NIR emission upon exposure to Hg 2+ . The overall results confirmed that this novel NIR-emitting aza-boron-dipyrromethene fluorescent probe with a large Stokes shift could serve as a colorimetric and fluorescent "turn-on" sensor for Hg 2+ in both solutions and living cells., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A near-infrared distyryl boron dipyrromethene-based sensor bearing one bis(1,2,3-triazole)amino receptor has been synthesized. This probe selectively and quickly binds to Hg 2+ and Cu 2+ ions in CH 3 CN/H 2 O (5:1 v/v) and exhibits remarkably blue-shifted absorption and fluorescence bands due to the inhibition of the intramolecular charge transfer process. The fluorescence changes of this probe upon binding to Hg 2+ or Cu 2+ ion are totally different, undergoing a ratiometric fluorescence enhancement (for Hg 2+ ) or a fluorescence quenching (for Cu 2+ ) mechanism. The corresponding vivid color changes can be easily seen by the naked eye. This probe was further introduced into Hela cells for living cell imaging and found to discriminate Hg 2+ and Cu 2+ ions through two near-infrared fluorescence emission channels. These overall results indicate that this Click-derived near-infrared BODIPY-based probe is potentially useful for ratiometric and discriminative detection of Hg 2+ and Cu 2+ ions in solutions and living cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Unlabelled: As the primary determinants of the clinical behaviors of human cancers, the discovery of cancer stem cells (CSCs) represents an ideal target for novel anti-cancer therapies (Kievit et al., 2014). Notably, CSCs are difficult to propagate in vitro, which severely restricts the study of CSC biology and the development of therapeutic agents. Emerging evidence indicates that CSCs rely on a niche that controls their differentiation and proliferation, as is the case with normal stem cells (NSCs). Replicating the in vivo CSC microenvironment in vitro using three-dimensional (3D) porous scaffolds can provide means to effectively generate CSCs, thus enabling the discovery of CSC biology. This paper presents our study on a novel alginate-based platform for mimicking the CSC niche to promote CSC proliferation and enrichment. In this study, we used a versatile mouse 4T1 breast cancer model to independently evaluate the matrix parameters of a CSC niche - including the material's mechanical properties, cytokine immobilization, and the composition of the extracellular matrix's (ECM's) molecular impact - on CSC proliferation and enrichment. On this basis, the optimal stiffness and concentration of hyaluronic acid (HA), as well as epidermal growth factor and basic fibroblast growth factor immobilization, were identified to establish the platform for mimicking the 4T1 breast CSCs (4T1 CSCs) niche. The 4T1 CSCs obtained from the platform show increased expression of the genes involved in breast CSC and NSC, as compared to general 2D or 3D culture, and 4T1 CSCs were also demonstrated to have the ability to quickly form a subcutaneous tumor in homologous Balb/c mice in vivo. In addition, the platform can be adjusted according to different parameters for CSC screening. Our results indicate that our platform offers a simple and efficient means to isolate and enrich CSCs in vitro, which can help researchers better understand CSC biology and thus develop more effective therapeutic agents to treat cancer., Statement of Significance: As the primary determinants of the clinical behaviors of human cancers, the discovery of cancer stem cells (CSCs) represents an ideal target for novel anti-cancer therapies. However, CSCs are difficult to propagate in vitro, which severely restricts the study of CSC biology and the development of therapeutic agents. Emerging evidence indicates that CSCs rely on a niche that controls their differentiation and proliferation, as is the case with normal stem cells (NSCs). Replicating the in vivo CSC microenvironment in vitro using three-dimensional (3D) porous scaffolds can provide means to effectively generate CSCs, thus enabling the discovery of CSC biology. In our study, a novel alginate-based platform were developed for mimicking the CSC niche to promote CSC proliferation and enrichment., (Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)