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The synthesis and structures of Fe, Co, and Zn halide complexes [MX2(H2L)] (M = Fe, X = Br; M = Co, Zn, X = Cl) of the N-donor extended dipyrromethane ligand H2L are described, from which it is clear that bond rearrangements from imine-pyrrole to amine-azafulvene tautomers occur on metal co-ordination, both in the solid state and in solution. In the structure of [FeBr2(H2L)], this H-migration results in a pendant amine that is involved in both inter- and intramolecular hydrogen bonds to the bromide ligands, so forming a dimer. As the tautomerisation renders the N–H protons less acidic, metal-based ligand substitution reactions can occur in favour of deprotonation. As such, the reaction between [MCl2(H2L)] (M = Co, Zn) and NaN3results in the formation of the bis(azide) complexes [M(N3)2(H2L)] which for Co displays both inter- and intramolecular N–HN3–Co hydrogen bonds in the solid state. In contrast, reactions of the dihalides with the lithium bases LiNMe2or LiMe (M = Fe), or reduction reactions with C8K (M = Fe, Co) result in the formation of the known dinuclear helicates [M2(L)2]. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) can differentiate into osteogenic, adipogenic, chondrogenic, myocardial, or neural lineages when exposed to specific stimuli, making them attractive for tissue repair and regeneration. We have used reporter gene-based imaging technology to track MSC transplantation or implantation in vivo. However, the effects of lentiviral transduction with the fluc-mrfp-ttk triple-fusion vector on the transcriptional profiles of MSCs remain unknown. In this study, gene expression differences between wild-type and transduced hMSCs were evaluated using an oligonucleotide human microarray. Significance Analysis of Microarray identified differential genes with high accuracy; RT-PCR validated the microarray results. Annotation analysis showed that transduced hMSCs upregulated cell differentiation and antiapoptosis genes while downregulating cell cycle, proliferation genes. Despite transcriptional changes associated with bone and cartilage remodeling, their random pattern indicates no systematic change of crucial genes that are associated with osteogenic, adipogenic, or chondrogenic differentiation. This correlates with the experimental results that lentiviral transduction did not cause the transduced MSCs to lose their basic stem cell identity as demonstrated by osteogenic, chondrogenic, and adipogenic differentiation assays with both transduced and wild-type MSCs, although a certain degree of alterations occurred. Histological analysis demonstrated osteogenic differentiation in MSC-loaded ceramic cubes in vivo. In conclusion, transduction of reporter genes into MSCs preserved the basic properties of stem cells while enabling noninvasive imaging in living animals to study the biodistribution and other biological activities of the cells. [ABSTRACT FROM AUTHOR]

Following extensive in vitro screening of new photosensitizers the purpose of the present study was to examine penetration as well as antibacterial efficacy of a lead photosensitizer against MRSA using an ex vivo porcine skin model. Two different applications were performed: (i) preincubation of bacteria in solution with a porphyrin-based photosensitizer XF73 and subsequent application on the ex vivo porcine skin; (ii) application of pure bacteria on the explants followed by an incubation with XF73 in a water–ethanol formulation for up to 60 min under occlusion. The localisation of XF73 was restricted to the stratum corneum. Different concentrations (0–10 µM) of XF73 and different incubation times (5–60 min) were used to determine phototoxicity against methicillin-resistant and methicillin-sensitive S. aureus, which was applied on the explants. Preincubation of S. aureus with 0.1 µM XF73 in solution prior to the application of these XF73-incubated bacteria on the skin demonstrates a higher efficacy (>3 log10) after irradiation. Antibacterial photodynamic inactivation resulted in a ∼1 log10 (0.1 µM)–3.64 ± 0.035 (10 µM) log10 growth reduction independently of the antibiotic resistance pattern of used S. aureus strains. Irradiation of applied bacteria without photosensitizer incubation did not show any marked decrease (<1 log10) of bacteria cell number, indicating a significant phototoxicity of the XF73. Histological evaluations of untreated and treated skin areas upon irradiation within 24 h showed no significant degree of necrosis or apoptosis determined by TUNEL-assay indicating that the porcine skin is still vital. This study demonstrates that this XF73 porphyrin-based photosensitizer had concentration-dependent differences in killing efficacy of MRSA in comparison to skin cells using an ex vivo porcine skin model. The results described here imply that topical delivery of XF73 may be considered as a possible treatment in patients with superficial infections of the skin. [ABSTRACT FROM AUTHOR]

A tripodal iminopyrrole provides an environment suited to the encapsulation of water through hydrogen-bonding, and the formation of metal complexes by deprotonation and imine–pyrrole tautomerisation. [ABSTRACT FROM AUTHOR]

Actinyl and actinyl-transition metal complexation by a polypyrrolic macrocycle with anthracenyl linkers between the N4-donor compartments was evaluated using relativistic density functional theory which predicts that a highly unusual cofacial bis-actinyl structure complex is stable. [ABSTRACT FROM AUTHOR]

A cobalt aquo-hydroxo complex of a ditopic Schiff-base pyrrole–crown ether macrocycle has been prepared and forms a rigid Pacman-clefted structure that assembles through hydrogen-bonding into a hexagonal wheel motif in the solid state. [ABSTRACT FROM AUTHOR]

A DFT study of the reduction and silylation of the uranyl U–O bond in a macrocyclic complex shows the importance of the initial dipotassiation in THF solution, and a slightly downhill reaction pathway for the oxo group functionalisation. [ABSTRACT FROM AUTHOR]

The separation of gallium from iron by solvent extraction from chloride media is challenging because the anionic chloridometalates, FeCl4− and GaCl4−, display similar chemical properties. However, we report here that the selective separation of gallium from iron in HCl solution can be achieved using the dual-purpose ionic liquid methyltrioctylammonium iodide in a solvent extraction process. In this case, the reduction of Fe3+ to Fe2+ by the iodide counterion was found to inhibit Fe transport, facilitating quantitative Ga extraction by the ionic liquid with minimal Fe extraction from 2 M HCl. [ABSTRACT FROM AUTHOR]