A Fluorescent Activatable AND‐Gate Chemokine CCL2 Enables In Vivo Detection of Metastasis‐Associated Macrophages

We report the novel chemical design of fluorescent activatable chemokines as highly specific functional probes for imaging subpopulations of immune cells in live tumours. Activatable chemokines behave as AND‐gates since they emit only after receptor binding and intracellular activation, showing enhanced selectivity over existing agents. We have applied this strategy to produce mCCL2‐MAF as the first probe for in vivo detection of metastasis‐associated macrophages in a preclinical model of lung metastasis. This strategy will accelerate the preparation of new chemokine‐based probes for imaging immune cell function in tumours.     

Vapor growth of GaxAl1−xSb

The vapor growth of Ga_xAl_1?xSb was experimentally studied using a closed tube transport technique. In the closed tube process with iodine as a transport agent, Ga_xAl_1?xSb was successfully grown on (111) oriented GaSb substrates at a relatively low temperature. The composition of the grown layer depended primarily on that of the source, and had only a small graded region (<0.5 μm) between the substrate and the epitaxial layer. The growth rate was almost constant irrespective of the growth time, whenever the other growth parameters were unchanged.     

Complanine, an inflammation-inducing substance isolated from the marine fireworm Eurythoe complanata

The marine fireworm, Eurythoe complanata, is known as a dangerous animal for humans because it induces skin inflammation through its small setae. Here, the inflammation-inducing substance was successfully isolated from the whole body using a methanolic extraction, and the inflammatory activity was determined using a bioassay. The structure was spectroscopically revealed to be a trimethylammonium with an unsaturated carbon chain and was named complanine. Complanine enhanced PKC activity in combination with TPA in vitro. This may explain the molecular mechanism behind its inflammation-inducing activity.     

Analysis of Cu segregation to oxide–metal interface of Ni‐based alloy in a metal‐dusting environment

Hard X‐ray photoelectron spectroscopy (HX‐PES) has been realized using high‐brilliance synchrotron radiation. High‐energy photon excitation enables us to probe photoelectrons with larger escape depth compared to conventional PES. This allows us to conduct, without destruction, a study of the embedded interface of materials as the oxide‐ metal interface. We apply HX‐PES to investigate for Cu segregation in the oxide–metal interface during metal‐dusting corrosion. The effective concentration of Cu in the segregation was estimated a few times higher than the bulk concentration. These results on the interface layer can explain the variation in the corrosion resistance. Copyright © 2008 John Wiley & Sons, Ltd.     

Formation of supramolecular polymers and discrete dimers of perylene bisimide dyes based on melamine-cyanurates hydrogen-bonding interactions

Melamine-linked perylene bisimide dyes (MPBIs) bearing an ethylene or trimethylene group as linker moieties were synthesized, and their self-aggregation and coaggregation with cyanurates through complementary triple hydrogen bonds have been investigated. UV/vis studies revealed that both the MPBIs self-assemble in nonpolar organic solvent through pi-pi stacking interaction between perylene cores, giving self-aggregates with nearly identical thermal stabilities. Upon addition of 1 equiv of cyanurate components, however, the stabilities of the resulting aggregates were dramatically changed between the two systems, suggesting the formation of different types of hydrogen-bonded supramolecular species. Dynamic light scattering and atomic force microscopic studies revealed that the system featuring ethylene linker moieties generates a discrete dimer of MPBI supported by two cyanurate molecules, whereas the system featuring trimethylene linker moieties affords extended supramolecular polymers hierarchically organizing into nanoscopic fibers. These results demonstrate that it is possible to obtain distinct supramolecular species by just changing the number of carbon atoms at the linker moieties of MPBI components. The present strategy for the fabrication of discrete or polymeric supramolecular assemblies should be applicable to other functional pi-conjugated molecules.     

Development of pyrrole-imidazole polyamide for specific regulation of human aurora kinase-A and -B gene expression

Pyrrole-imidazole polyamide (PIP) is a nuclease-resistant novel compound that inhibits gene expression through binding to the minor groove of DNA. Human aurora kinase-A (AURKA) and -B (AURKB) are important regulators in mitosis during the cell cycle. In this study, two specific PIPs (PIP-A and PIP-B) targeting AURKA and AURKB promoter regions were designed and synthesized, and their biological effects were investigated by several in vitro assays. PIP-A and PIP-B significantly inhibited the promoter activities, mRNA expression, and protein levels of AURKA and AURKB, respectively, in a concentration-dependent manner. Moreover, 1:1 combination treatment with both PIPs demonstrated prominent antiproliferative synergy (CI value [ED(50)] = 0.256) to HeLa cells as a result of inducing apoptosis-mediated severe catastrophe of cell-cycle progression. The novel synthesized PIP-A and PIP-B are potent and specific gene-silencing agents for AURKA and AURKB.     

Reversible mechanochromic luminescence of [(C6F5Au)2(mu-1,4-diisocyanobenzene)

Reversible mechanochromic luminescence of [(C6F5Au)2(mu-1,4-diisocyanobenzene)] is reported. Grinding of the complex induced a photoluminescent color change, which was restored by exposure to a solvent. This cycle was repeated 20 times with no color degradation in the emissions. Their optical properties, X-ray crystallographic analysis, IR, and XRD measurements strongly suggested that the change in the molecular arrangement is responsible for this mechanochromic property. Intermolecular aurophilic bondings presumably play a key role in the altered emission.     

Partitioning of anti-inflammatory steroid drugs into phosphatidylcholine and phosphatidylcholine-cholesterol small unilamellar vesicles as studied by second-derivative spectrophotometry

The partition coefficients (Kps) of six anti-inflammatory steroid drugs, dexamethasone (DMS), betamethasone (BMS), triamcinolone acetonide (TCLA), fluocinolone acetonide (FCLA), betamethasone 17,21-dipropionate (BMSDP), and clobetasole propionate (CBSP), for phosphatidylcholine (PC), and PC-cholesterol small unilamellar vesicles (SUVs) were determined by a second-derivative spectrophotometric method. The Kp values were obtained with a relative standard deviation of below 10% and the following order was observed: BMS< or =DMS相似文献   

Heteropolynuclear complexes of 3,5-dimethylpyrazolate [Pt2M4(Me2pz)8] (M = Ag, Cu). Highly luminescent character of the triplet excited state based on mixed-metal cores

The platinum dimer and heteropolynuclear platinum complexes of 3,5-dimethylpyrazolate, [Pt2M4(mu-Me2pz)8] [M = H (1), Ag (2), Cu (3)], were synthesized and structurally characterized. They exhibit yellow, sky-blue, and orange luminescence, respectively, in the solid state. The absorption bands of 2 and 3 are mainly assigned to the combination of the metal-metal-to-ligand charge-transfer and [Pt2 --> Pt2M4] transitions by the time-dependent density functional theory (DFT) method. DFT calculations also indicate that the emissive states of 2 and 3 are 3[Pt2 --> Pt2Ag4] and 3[Cu(d) --> Pt2Cu4], respectively.     

Films Consisting of Innumerable Tapered Nanopillars of Mesoporous Silica for Universal Antireflection Coatings

Films with a fine structure consisting of innumerable nanopillars of mesoporous silica (MPS) are formed by a reactive ion etching process with a fluorine‐containing gas. Each nanopillar has a tapered shape with a uniform height, which effectively suppresses reflection by the formation of an ideal graded refractive index structure. The nanopillars are spontaneously formed under low‐pressure conditions, wherein locally deposited Al?F compounds, originating from an alumina plate in the etching chamber, work as a fine etching mask. The high etching rate of the MPS film allows a very high aspect ratio of the nanopillars. The refractive index of the MPS nanopillars can be universally tuned by a controlled incorporation of TiO₂ into the mesopores, which results in effective reduction of reflectance on a given substrate. The outstanding antireflection performance is experimentally demonstrated for glass substrates with a wide refractive index range.