Search

A systematic route is developed for the synthesis of a series of dodeca- to octadecamannopyranoside G(0) dendrimers by using triazole chemistry. A new family of glycodendrimer scaffolds are prepared by Cu(I)-catalyzed [1,3]-dipolar cycloadditions by using sulfurated dendritic scaffolds bearing alkyne functionalites and novel TRIS derivatives.

Nanoparticle-based cell differentiation therapy has attracted increasing research interest as it is a promising substitute for conventional cancer treatment methods. Here, the topological insulator bismuth selenide nanoparticle (Bi 2 Se 3 NP) was core-shelled with silver (Ag@Bi 2 Se 3 ) to represent remarkable biocompatibility and plasmonic features (ca. 2.3 times higher than those of Ag nanoparticle). Moreover, a newly developed RNA three-way junction (3WJ) structure was designed for the quad-functionalization of any type of nanoparticle and surface. One leg of the 3WJ was attached to the Ag@Bi 2 Se 3 , and the other leg harbored a cell-penetrating RNA and a florescence tag. The third leg was designed to inhibit micro-RNA-17 (miR-17) and to further release retinoic acid (RA). A new drug delivery mechanism was developed for the slow release of RA inside the cytosol based on the prerequisite inhibition of miR-17 using a strand displacement strategy. In this paper, we report a simple methodology for resolving the hydrophobicity challenges of RA by its conjugation with a RNA strand (RA/R) through a stimulus-responsive cross-linker. The developed nanobiohybrid material could fully differentiate SH-SY5Y cancer cells into neurons and stop their growth in 6 days without requiring sequential treatments which has not been reported yet. Using a surface-enhanced Raman spectroscopy technique, the RA delivery and the cell differentiation process were monitored nondestructively in real time. The fabricated nanobiohybrid material could open the new horizons in the fabrication of different diagnostic/therapeutic agents.

A series of europium and terbium complexes based on a functionalized triazacyclononane carboxylate or phosphinate macrocyclic ligand is described. The influence of the anionic group, that is, carboxylate, methylphosphinate, or phenylphosphinate, on the photophysical properties was studied and rationalized on the basis of DFT calculated structures. The nature, number, and position of electron-donating or electron-withdrawing aryl substituents were varied systematically within the same phenylethynyl scaffold in order to optimize the brightness of the corresponding europium complexes and investigate their two-photon absorption properties. Finally, the europium complexes were examined in cell-imaging applications, and selected terbium complexes were studied as potential oxygen sensors., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein, we provide some structural evidence of the complexation color-change of murexide solutions in presence of lanthanide, which has been used for decades in complexometric studies. For Ln = Sm to Lu and Y, the compounds crystallize as monomeric [Ln(Murex)3]⋅11 H2O with an N3O6 tricapped square-antiprism environment, which are stable up to 250 °C. Single-ion magnet (SIM) behavior is then observed on the Yb(III) derivative in an original nine-coordinated environment. In-field slow relaxation (Δ = (15.6±1) K; τ0 = 2.73×10(-6) s) is observed with a very narrow distribution of the relaxation time (αmax = 0.09). Magnetic and photophysical properties can be correlated. On one hand the analysis of NIR emission spectrum permits to have access to crystal field parameters and to compare them with those extracted from dc measurements. On the other hand, magnetic measurements permit to identify the nature of the MJ states involved in the (2)F5/2 → (2)F7/2 luminescence spectrum. The gap between the low-lying states is in agreement with the energy barrier obtained from magnetic slow-relaxation measurement., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We have synthesized a novel class of dendrimers, consisting of a polysulfurated pyrene core with appended poly(thiophenylene) dendrons (PyG0, PyG1, and PyG2, see Scheme 1), which exhibit remarkable photophysical and redox properties. In dichloromethane or cyclohexane solution they show a strong, dendron-localized absorption band with a maximum at around 260 nm and a band in the visible region with a maximum at 435 nm, which can be assigned to the pyrene core strongly perturbed by the four sulfur substituents. The dendrimers exhibit a strong (Phi=0.6), short-lived (tau=2.5 ns) core-localized fluorescence band with maximum at approximately 460 nm in cyclohexane solution at 293 K. A strong fluorescence is also observed in dichloromethane solution at 293 K, in dichloromethane/chloroform rigid matrix at 77 K, and in the solid state (powder) at room temperature. The dendrimers undergo reversible chemical and electrochemical one-electron oxidation with formation of a strongly colored deep blue radical cation. A second, reversible one-electron oxidation is observed at more positive potential values. The photophysical and redox properties of the three dendrimers are finely tuned by the length of their branches. The strong blue fluorescence and the yellow to deep blue color change upon reversible one-electron oxidation can be exploited for optoelectronic devices.