Luminescent Ru(ii)-thiol modified silver nanoparticles for lysosome targeted theranostics.

Silver nanoparticles (AgNPs) modified by luminescent Ru(ii) complexes not only possess bright red fluorescence but also can target lysosomes. Cell imaging and a cytotoxicity study suggest that Ru1-2·AgNPs may act as a potential theranostic agent.

G-quadruplex and duplex DNA binding studies of novel Ruthenium(II) complexes containing ascididemin ligands.

In this paper, three new Ruthenium(II) polypyridyl complexes containing ascididemin (ASC) as main ligand have been synthesized and characterized. Their interactions with different G-quadruplex (Htelo, c-myc and c-kit) (Htelo: human telomeric DNA, c-myc: cellular-myelocytomatosis viral oncogene, c-kit: oncogene c-kit promoter sequences) and duplex (ds26) DNA sequences were comparatively studied with the free ligand ASC by a series of spectroscopic techniques including UV-vis (ultraviolet-visible) spectroscopy, FID (fluorescent intercalator displacement) assay, and FRET (fluorescence resonance energy transfer) melting assay. Molecular docking studies were also performed to support the binding mode of the compounds with G-quadruplex DNA. Results indicated that [Ru(bpy)2ASC]·(PF6)2 (1), [Ru(phen)2ASC]·(PF6)2 (2), [Ru(tatp)2ASC]·(PF6)2 (3) (bpy = 2,2'­bipyridine, phen = 1,10­phenanthroline, tatp = 1,4,8,9­tetra­aza­triphenylene) and ASC can effectively bind G-quadruplex and duplex DNA and stabilization ability lies in the order 3 > 2 > 1 > ASC. Complex 3 was determined to be the most promising candidate for further in vitro studies and potential anticancer drug.

Regulation of multi-factors (tail/loop/link/ions) for G-quadruplex enantioselectivity of Δ- and Λ- [Ru(bpy)2(dppz-idzo)]2.

Chiral recognition of DNA molecules is important because much evidence has indicated that transformations of chirality and diverse conformations of DNA are involved in a series of key biological events. Among these, enrichment of G-quadruplexes (GQs) in the genome, and the exploration of their multiple structures, has aroused great interest. Herein, we compared nearly 100 different sequences with 3'-tail sequences of variable length or different linkers or diverse loops and mutative ionic concentrations. All sequences were capable of forming stable GQs, with fluorescence signal enhancement upon binding with Δ- and Λ- [Ru(bpy)2(dppz-idzo)]2+ (Δ/Λ-1). Our results show that multiple factors, including the 3'-tail length, linkers, loop length and ionic concentration, regulate the enantioselectivity of GQs. Furthermore, molecular docking simulations revealed that chiral recognition of GQs depends on the binding site. To the best of our knowledge, this is the first systematic study regarding the regulation of multi-factors for GQ selectivity of chiral Ru-complexes. These results will serve as a useful reference for enantioselective recognition of genomic GQs and may facilitate the development of chiral anticancer agents for targeting GQs.

Coordination polymer nanoparticles from nucleotide and lanthanide ions as a versatile platform for color-tunable luminescence and integrating Boolean logic operations.

Novel supramolecular coordination polymer nanoparticles (CPNs) were synthesized via the self-assembly of guanosine monophosphate (GMP) and lanthanide ions (Ln3+, including Tb3+, Eu3+ and Ce3+) in aqueous solution. These CPNs (GMP/Tb3+, GMP/Eu3+ and GMP/Ce3+) have an identical coordination environment but exhibit completely different luminescence properties responding to external stimuli such as dipicolinic acid (DPA), ethylene diamine tetraacetic acid (EDTA), pH and metal ions, which has inspired us to tune the emission color of the CPNs and perform multiple logic operations. Firstly, color-tunable luminescence from red to green can be easily achieved by modulating the doping ratio of Tb3+ and Eu3+ into GMP. Notably, trichromatic white light emitting CPNs can be successfully realized by simultaneously doping Tb3+, Eu3+ and Ce3+ into the host or just adjusting the pH of the solution. What's more, by employing GMP/Tb3+ CPNs as a logic operator, we have achieved the implementation of multilayered gate cascades (INH-INH, NOR-OR). When GMP/Eu3+ CPNs served as a logic operator, the logic elements can be integrated as another combinatorial gate (AND-INH). Moreover, by employing the red emission of Eu3+ and blue emission of GMP as the dual-output signal transducer, a set of parallel logic gates was established successfully. These results help elucidate the design rules by which simple logic can be integrated to construct cascaded logic gates and expand the applications of CPNs in light-emitting diode (LED) lamps and biological systems.