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Stolarczyk J.K.,Ludwig Maximilians University of Munich | Deak A.,Institute for Technical Physics and Materials Science | Brougham D.F.,National Institute for Cellular Biotechnology | Brougham D.F.,University College Dublin
Advanced Materials

The current state of the art in the use of colloidal methods to form nanoparticle assemblies, or clusters (NPCs) is reviewed. The focus is on the two-step approach, which exploits the advantages of bottom-up wet chemical NP synthesis procedures, with subsequent colloidal destabilization to trigger assembly in a controlled manner. Recent successes in the application of functional NPCs with enhanced emergent collective properties for a wide range of applications, including in biomedical detection, surface enhanced Raman scattering (SERS) enhancement, photocatalysis, and light harvesting, are highlighted. The role of the NP–NP interactions in the formation of monodisperse ordered clusters is described and the different assembly processes from a wide range of literature sources are classified according to the nature of the perturbation from the initial equilibrium state (dispersed NPs). Finally, the future for the field and the anticipated role of computational approaches in developing next-generation functional NPCs are briefly discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Source

Corry A.J.,Dublin City University | Goel A.,Dublin City University | Kenny P.T.M.,Dublin City University | Kenny P.T.M.,National Institute for Cellular Biotechnology
Inorganica Chimica Acta

Standard peptide coupling reactions were use to prepare the N-(ferrocenyl) 2 and N-(ferrocenoyl) 2 cystine dimethyl ester derivatives 4-11. The ferrocene carboxylic acids 1 and 3 were treated with 1-hydroxybenzotriazole (HOBt), N-(3-dimethylaminopropyl)-N′- ethylcarbodiimide hydrochloride (EDC), l-cystine methyl ester hydrochloride and triethylamine in dichloromethane at 0 °C to furnish compounds 4-9. The preparation of compounds 10 and 11 employed the dipeptide derivatives (glycine) 2-l-cystine dimethyl ester and (β-alanine) 2-l-cystine dimethyl ester respectively. The N-(ferrocenyl) 2 and N-(ferrocenoyl) 2 cystine dimethyl ester derivatives 4-11, which are potential anion sensing agents, were spectroscopically characterized by a combination of 1H NMR, 13C NMR, IR, UV, DEPT-135 and 1H- 13C COSY (HMQC) spectroscopy, mass spectrometry and cyclic voltammetry. The electrochemical detection of dihydrogen phosphate and adenosine nucleotide anions in aqueous electrolyte by monolayers of {N-(ferrocenoyl)-β-alanine} 2-l-cystine dimethyl ester 11 immobilized on gold electrodes using cyclic voltammetry is described. Immobilization of this receptor on a gold electrode surface enabled the recognition process to be detected in aqueous media. The recognition process is as a result of electrostatic interactions between the ferricenium cation and the anion, and hydrogen bonding interactions between the peptide amide bonds and the anion. The complexation process was amperometrically sensed via a reduction in the peak current of the ferrocene/ferricenium redox couple. A linear relationship (R 2 = c. 0.99) was observed between anion concentration and change in peak current in both cases. © 2011 Elsevier B.V. All rights reserved. Source

Kelly J.,National Institute for Cellular Biotechnology | Kavanagh K.,National Institute for Cellular Biotechnology
Journal of Medical Microbiology

The echinocandins (e.g. caspofungin) function by inhibiting the synthesis of 1,3-β-glucan in the fungal cell wall. While the potent antifungal activity of caspofungin has been well characterized in mammals, this study investigated the in vivo antifungal effect of caspofungin using larvae of the insect Galleria mellonella. Caspofungin was successful in increasing the survival of larvae that were inoculated with Candida albicans 1 h before the drug was administered, particularly when a concentration of 0.19 μg ml -1 was used. Pre-injecting larvae with caspofungin also increased their survival when they were inoculated with either Staphylococcus aureus or C. albicans. Caspofungin administration resulted in an increase in the number of circulating immune cells (haemocytes), an increase in the expression of the genes encoding IMPI and transferrin, and an increase in the expression of a number of proteins (identified by liquid chromatography-mass spectrometry) some of which have immune functions. This work indicates that administration of caspofungin can increase the survival of infected G. mellonella larvae, and this is due to the antifungal properties of caspofungin and also to the ability of caspofungin to prime the insect's immune response. © 2011 SGM. Source

Coughlan C.A.,Royal College of Surgeons in Ireland | Chotirmall S.H.,Royal College of Surgeons in Ireland | Renwick J.,Trinity College Dublin | Hassan T.,Royal College of Surgeons in Ireland | And 12 more authors.
American Journal of Respiratory and Critical Care Medicine

Rationale: Aspergillus fumigatus (A. fumigatus) in cystic fibrosis (CF) is increasingly recognized. Although allergic bronchopulmonary aspergillosis (ABPA) leads to deterioration of pulmonary function, the effect of A. fumigatus colonization in the absence of ABPA remains unclear. Objectives: To address this, we examined individuals with CF with A. fumigatus who were ABPA negative to identify the effects of itraconazole therapy on Aspergillus-induced lung inflammation. Methods: The effect of A. fumigatus on nuclear vitamin D receptor (VDR) expression was investigated using qRT-PCR and Western blotting. IL-5 and IL-13 levels were quantified by ELISA. The effect of itraconazole was assessed by a combination of high-resolution computed tomography, lung function test, and microbiological analysis. Measurements and Main Results: We demonstrate that A. fumigatus down-regulates VDR in macrophages and airway epithelial cells and that the fungal metabolite gliotoxin (Gt) is themain causative agent. Gt overcame the positive effect of 1,25-OH vitamin D3 on VDR expression in vitro, resulting in increased IL-5 and IL-13 production. In vivo, A. fumigatus positivity was associated with increased Gt in CF bronchoalveolar lavage fluid and increased bronchoalveolar lavage fluid levels of IL-5 and IL-13. After airway eradication of A. fumigatus with itraconazole, we observed decreased Gt, IL-5 and IL-13, improved respiratory symptoms, and diminished high-resolution computed tomographymosaic pattern consistent with sustained pulmonary function. Conclusions: This study provides a rationale for the therapeutic effect of itraconazole and implied that the therapeutic potential of vitamin D supplementation in preventing ABPA is only feasible with concurrent elimination of A. fumigatus to permit VDR expression and its positive functional consequences. Copyright © 2012 by the American Thoracic Society. Source

Butler W.E.,National Institute for Cellular Biotechnology | Butler W.E.,Dublin City University | Kelly P.N.,National Institute for Cellular Biotechnology | Kelly P.N.,Dublin City University | And 6 more authors.
Applied Organometallic Chemistry

A series of N-(ferrocenylmethyl amino acid) fluorinated benzene-carboxamide derivatives and have been synthesized by coupling ferrocenylmethyl amine 3 with various substituted N-(fluorobenzoyl) amino acid derivatives using the standard N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, 1-hydroxybenzotriazole protocol. The amino acids employed in this study were glycine and L-alanine. All of the compounds were fully characterized using a combination of 1H NMR, 13C NMR, 19F NMR, distortionless enhancement by polarization transfer (DEPT)-135, 1H-1H correlation spectroscopy (COSY) and 1H-13C COSY (heteronuclear multiple-quantum correlation) spectroscopy. The compounds were biologically evaluated on the oestrogen-positive MCF-7 breast cancer cell line. Compounds, and exhibited cytotoxic effects on the MCF-7 breast cancer cell line. N-(Ferrocenylmethyl-L- alanine)-3,4,5-trifluorobenzene-carboxamide () was the most active compound, with an IC50 value of 2.84 μm. Compounds, and had lower IC 50 values than that found for the clinically employed anticancer drug cisplatin (IC50 = 16.3 μm against MCF-7). Guanine oxidation studies confirmed that was capable of generating oxidative damage via a reactive oxygen species-mediated mechanism. Copyright © 2013 John Wiley & Sons, Ltd. Source

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