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Université de Fribourg

Reduction in (pro-)inflammatory responses of lung cells exposed in vitro to diesel exhaust treated with a non-catalyzed diesel particle filter

Steiner, Sandro ; Czerwinski, Jan ; Comte, Pierre ; Müller, Loretta L. ; Heeb, Norbert V. ; Mayer, Andreas ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: Atmospheric Environment, 2013, vol. 81, p. 117–124

Increasingly stringent regulation of particulate matter emissions from diesel vehicles has led to the widespread use of diesel particle filters (DPFs), the effect of which on exhaust toxicity is so far poorly understood. We exposed a cellular model of the human respiratory epithelium at the air-liquid interface to non-catalyzed wall-flow DPF-filtered diesel exhaust and compared the resulting...

Université de Fribourg

Comparison of the toxicity of diesel exhaust produced by bio- and fossil diesel combustion in human lung cells in vitro

Steiner, Sandro ; Czerwinski, Jan ; Comte, Pierre ; Popovicheva, Olga ; Kireeva, Elena ; Müller, Loretta ; Heeb, Norbert ; Mayer, Andreas ; Fink, Alke ; Rothen-Rutishauser, Barbara

In: Atmospheric Environment, 2013, vol. 81, p. 380–388

Alternative fuels are increasingly combusted in diesel- and gasoline engines and the contribution of such exhausts to the overall air pollution is on the rise. Recent findings on the possible adverse effects of biodiesel exhaust are contradictive, at least partly resulting from the various fuel qualities, engine types and different operation conditions that were tested. However, most of the...

Université de Fribourg

Efficient electronic communication of two ruthenium centers through a rigid ditopic N-heterocyclic carbene linker

Nussbaum, Michael ; Schuster, Oliver ; Albrecht, Martin

In: Chemistry – A European Journal, 2013, vol. 19, no. 51, p. 17517–17527

A ditopic benzobis(carbene) ligand precursor was prepared that contained a chelating pyridyl moiety to ensure co-planarity of the carbene ligand and the coordination plane of a bound octahedral metal center. Bimetallic ruthenium complexes comprising this ditopic ligand [L₄Ru-C,N-bbi-C,N-RuL₄] were obtained by a transmetalation methodology...

Université de Fribourg

Synthesis of nanometer-sized rod–coil block copolymers

König, Hannah M. ; Kilbinger, Andreas F. M.

In: CHIMIA International Journal for Chemistry, 2013, vol. 67, no. 11, p. 788–790

We present the solid-supported synthesis of a linear rigid rod-like tetradeca(p-benzamide) nanorod as well as a pentadeca( p -benzamide) nanorod carrying an amide N-hexyl side chain at the center of the rod (on the 8th amino acid of the molecule). These nanorods were conjugated with solubilizing poly(ethylene glycol) chains and their solution aggregation was investigated. Both rod–coil block...

Université de Fribourg

The search for relay stations. Long-distance electron transfer in peptides

Bernd, Giese ; Kracht, Sonja ; Cordes, Meike

In: CHIMIA International Journal for Chemistry, 2013, vol. 67, no. 12, p. 855–858

Nature uses peptide aggregates as soft materials for electron transfer over long distances. These reactions occur in a multistep hopping reaction with various functional groups as relay stations that are located in the side chain and in the backbone of the peptides.

Université de Fribourg

Polymorphism, what it is and how to identify it: a systematic review

Brog, Jean-Pierre ; Chanez, Claire-Lise ; Crochet, Aurélien ; Fromm, Katharina M.

In: RSC Advances, 2013, vol. 3, no. 38, p. 16905–16931

This review on polymorphism is a personal, non-comprehensive view on the field of polymorphism – a term which is often misused. Indeed, the discussion about polymorphism and related terms is still ongoing in the area of crystal engineering. This is why we felt it timely to look into the historical development of its definition and to delimit it. A short introduction to thermodynamic aspects...

Université de Fribourg

A family of immobilizable chiral bis(pinenebipyridine) ligands

Pöllnitz, Alpár ; Skupienski, Radek ; Stoeckli-Evans, Helen ; Crochet, Aurélien ; Silvestru, Anca ; Fromm, Katharina M. ; Mamula, Olimpia

In: Synlett, 2013, vol. 24, no. 19, p. 2555–2558

New enantiopure ligands containing two (–)-5,6-pinenebipyridine units connected by a bridge situated in position 6′ of the bipyridines have been prepared. The chemically addressable groups of the bridging (hydroxyl or keto) can be covalently bound to various supports in order to heterogenize the ligand.

Université de Fribourg

Controlled tautomerism – switching caused by an ‘underground’ anionic effect

Antonov, Liudmil ; Deneva, Vera ; Kurteva, Vanya ; Nedeltcheva, Daniela ; Crochet, Aurélien ; Fromm, Katharina M.

In: RSC Advances, 2013, vol. 3, no. 47, p. 25410–25416

In a previous communication, we demonstrated a conceptual idea for a tautomeric switching system based on implementation of a flexible piperidine unit in 4- (phenyldiazenyl)naphthalen-1-ol (1). The results showed that a directed shift in the position of the tautomeric equilibrium can be achieved through protonation/deprotonation in a number of solvents. However, the effect of the counter ion...

Université de Fribourg

Bioinorganic chemistry of silver: its interactions with amino acids and peptides

Fromm, Katharina M.

In: CHIMIA International Journal for Chemistry, 2013, vol. 67, no. 12, p. 851–854

Silver and its compounds have been used for centuries for e.g. water storage, burn wounds or as eye ointment. Almost forgotten after the discovery of antibiotics, silver chemistry has had a revival over the past years as a means to combat multi-resistant bacteria. Although the details of its mechanism of action are still unknown, silver seems to be efficient as it interacts with many biomolecular...

Université de Fribourg

Fluorescence-encoded gold nanoparticles: library design and modulation of cellular uptake into dendritic cells

Rodriguez-Lorenzo, Laura ; Fytianos, Kleanthis ; Blank, Fabian ; Garnier, Christophe von ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Small, 2014, vol. 10, no. 7, p. 1341–1350

In order to harness the unique properties of nanoparticles for novel clinical applications and to modulate their uptake into specific immune cells we designed a new library of homo- and hetero-functional fluorescence-encoded gold nanoparticles (Au-NPs) using different poly(vinyl alcohol) and poly(ethylene glycol)-based polymers for particle coating and stabilization. The encoded particles were...