Some Ru complexes have extremely promising anticancer or antibacterial properties, but their poor H 2 O solubility and/or low stability of many Ru complexes in aqueous solution under physiological conditions and/or metabolic/biodistribution profile prevent their therapeutic use. To overcome these drawbacks, various strategies have been developed to improve the delivery of these compounds to their target tissues. The first strategy is based on physical encapsulation of Ru complexes in carriers, such as polymeric micelles, microparticles, nanoparticles and polymer-lipid hybrids, which enabled the delivery and controlled release of the active Ru drug candidate. The second strategy involves covalent conjugation of the ruthenium complex to a polymer to give a prodrug that can be converted to the active drug at a more controllable rate. In this Review, we provide an overview of recent developments in polymer encapsulation of Ru complexes for biological and medicinalapplications, and place particular Here, the presence of Ru centre enable 3D geometries not available with organic chemistry. For example, the Ru(II) complex DW1 and its enantiomer DW2 mimic the shape of the alkaloid staurospaurine, and complexes thus also exhibit impressive kinase inhibition activity (targeting glycogen synthase kinase 3 (GSK3) signalling) and cytotoxicity in human melanoma cancer cells 38. The biological properties of Ru complexes-such as bioactivity, cellular uptake and intracellular distribution-depend, among others, on chemical properties such as electronegativity, chemical hardness, stereochemistry and net charge of the Ru centre. Ru drug candidates often feature strongly bound ligands, such as amine, phosphine, π-bound arenes and cyclopentadienyl derivatives. These are complemented by weakly bound ligands such as Cl − or RCO 2 − , which can be displaced by chelators or simply when an excess of competitive ligands is present. As is the case for reduced Pt derivatives, the lower-valent Ru(II) and Ru(III) complexes have favourable ligand exchange kinetics with O-donor and N-donor ligands. Ru complexes have several other advantages for biological and medicinal applications, including their usual low (or zero) toxicity to healthy tissues and their distinct mode of action. Indeed, they operate through different pathways to most Pt-based drugs, which typically only interact with DNA (BOX 1). Ru(II) and Ru(III) complexes have similar ligand exchange kinetics to the Pt(II) complexes used as antineoplastic drugs 39. For small ligands such as H 2 O, the ligand exchange rate on the Ru centre is on the order of hours, which is similar to the timescale of cell division in many cell types 40. Furthermore, Ru can bind biomolecules responsible for Fe solubilization and transport in plasma, including serum transferrin and albumin. Rapidly dividing cells, such as cancer cells, require more Fe, which leads to an upregulation of the number of transferrin receptors at the cell surface 41. Consequently, Ru complexes have been proposed to preferentially targ...

Polymer springs that twist under irradiation with light, in a manner that mimics how plant tendrils twist and turn under the effect of differential expansion in different sections of the plant, show potential for soft robotics and the development of artificial muscles. The soft springs prepared using this protocol are typically 1 mm wide, 50 μm thick and up to 10 cm long. They are made from liquid crystal polymer networks in which an azobenzene derivative is introduced covalently as a molecular photo-switch. The polymer network is prepared by irradiation of a twist cell filled with a mixture of shape-persistent liquid crystals, liquid crystals having reactive end groups, molecular photo-switches, some chiral dopant and a small amount of photoinitiator. After postcuring, the soft polymer film is removed and cut into springs, the geometry of which is determined by the angle of cut. The material composing the springs is characterized by optical microscopy, scanning electron microscopy and tensile strength measurements. The springs operate at ambient temperature, by mimicking the orthogonal contraction mechanism that is at the origin of plant coiling. They shape-shift under irradiation with UV light and can be pre-programmed to either wind or unwind, as encoded in their geometry. Once illumination is stopped, the springs return to their initial shape. Irradiation with visible light accelerates the shape reversion.

A novel nanohybrid structure was synthesized by assembling gold nanoparticles on polymerized polydiacetylene nanotubes. Combination of the nanohybrid with gallacetophenone afforded an efficient cooperative co-catalytic system for the oxidative coupling of primary amines into imines. The system is highly efficient and sustainable as it operates in high yields using minimal amounts of the metal and the quinone, under ambient atmosphere, at room temperature, in water, and is easily recycled.

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Phosphonated molecules, featuring a half‐cage structure and a N‐lateral chain with additional metal coordinating groups were designed as ligands of metal cations. These compounds were synthesized by a Diels–Alder (DA) strategy, using 1‐diethoxyphosphoryl‐1,3‐butadiene and a series of N‐substituted maleimides as dienophiles. Two cycloadducts, bearing a terminal primary alcohol and a terminal iodide, respectively, were used as key intermediates for further functionalizations. Metal coordination properties of the ligands equipped with functionalized N‐lateral chains were proven by an ESI‐HRMS study. The stoichiometry of one selected EuIII complex with a diphosphonated ligand was determined by photoluminescence spectroscopy in emission mode.

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A layer-by-layer approach is used to anchor small gold nanoparticles onto organic nanotubes resulting from the selfassembly and polymerization of diacetylene-containing nitrilotriacetic amphiphiles. The obtained nanotube-gold hybrid is used as a catalyst for the aerobic oxidation of various silanes. With minimal gold loading (0.05 mol%), all substrates are converted into the corresponding silanols with hydrogen gas as the only by-product. The catalyst operates under mild conditions and can be easily recycled, losing neither activity nor selectivity.initial studies on the oxygen-water-mediated silane oxidation mostly involved homogeneous transition metals [7][8][9][10][11] as catalytic species, recent developments showed that heterogeneous catalytic systems were also appealing substitutes (Scheme 1 ). [12][13][14][15][16][17] These systems usually operate under mild conditions in an effi cient and selective manner, while allowing the recycling of the catalyst. [ 18,19 ] For example, nanoporous gold, [ 12 ] supported silver or gold nanoparticles, [14][15][16] and carbon nanotube-gold nanohybrids, [ 20 ] can be cited as heterogeneous catalysts employed in this context. In this article, the aerobic oxidation of silanes using gold nanoparticles supported on organic nanotubes (ONTs) is reported.