Université de Fribourg

A hydrofluoric acid-free method to dissolve and quantify silica nanoparticles in aqueous and solid matrices

Bossert, David ; Urban, Dominic A. ; Maceroni, Mattia ; Ackermann-Hirschi, Liliane ; Haeni, Laetitia ; Yajan, Phattadon ; Spuch-Calvar, Miguel ; Rothen-Rutishauser, Barbara ; Rodriguez-Lorenzo, Laura ; Petri-Fink, Alke ; Schwab, Fabienne

In: Scientific Reports, 2019, vol. 9, no. 1, p. 7938

As the commercial use of synthetic amorphous silica nanomaterials (SiO2-NPs) increases, their effects on the environment and human health have still not been explored in detail. An often-insurmountable obstacle for SiO2-NP fate and hazard research is the challenging analytics of solid particulate silica species, which involves toxic and corrosive hydrofluoric acid (HF). We therefore developed...

Université de Fribourg

Structure and sedimentation kinetics of dense suspensions of fibroblast cells

Zenuni, Arbnor ; Zhang, Chi ; Haeni, Laetitia ; Rothen-Rutishauser, Barbara ; Scheffold, Frank

In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 1, p. 43–46

We investigate the structure and the dynamics of dense suspensions of NIH 3T3 fibroblast cells. Using two-photon microscopy we obtain three dimensional (3D) images from which the size and the packing structure of the dense cell suspensions can be extracted. In addition, we analyse the global time-dependent behaviour of the suspensions by time-lapse measurements of cell sedimentation. Since...

Université de Fribourg

Templated assembly of pore-forming peptides in lipid membranes

Fennouri, Aziz ; List, Jonathan ; Dupasquier, Jessica ; Haeni, Laetitia ; Vanni, Stefano ; Rothen-Rutishauser, Barbara ; Mayer, Michael

In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 1, p. 59–62

Pore-forming peptides are of interest due to their antimicrobial activity and ability to form gateways through lipid membranes. Chemical modification of these peptides makes it possible to arrange several peptide monomers into well-defined pore-forming structures using various templating strategies. These templated super-structures can exert antimicrobial activity at significantly lower total...

Université de Fribourg

Dynamic and biocompatible thermo-responsive magnetic hydrogels that respond to an alternating magnetic field

Crippa, Federica ; Moore, Thomas L. ; Mortato, Mariangela ; Geers, Christoph ; Haeni, Laetitia ; Hirt, Ann M. ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Journal of Magnetism and Magnetic Materials, 2017, vol. 427, p. 212–219

Magnetic thermo-responsive hydrogels are a new class of materials that have recently attracted interest in biomedicine due to their ability to change phase upon magnetic stimulation. They have been used for drug release, magnetic hyperthermia treatment, and can potentially be engineered as stimuli-responsive substrates for cell mechanobiology. In this regard, we propose a series of magnetic...