Université de Fribourg

Removal of cells from body fluids by magnetic separation in batch and continuous mode: influence of bead size, concentration, and contact time

Bohmer, Nils ; Demarmels, Nino ; Tsolaki, Elena ; Gerken, Lukas ; Keevend, Kerda ; Bertazzo, Sergio ; Lattuada, Marco ; Herrmann, Inge K.

In: ACS Applied Materials & Interfaces, 2017, vol. 9, no. 35, p. 29571–29579

The magnetic separation of pathogenic compounds from body fluids is an appealing therapeutic concept. Recently, removal of a diverse array of pathogens has been demonstrated using extracorporeal dialysis-type devices. The contact time between the fluid and the magnetic beads in such devices is limited to a few minutes. This poses challenges, particularly if large compounds such as bacteria or...

Université de Fribourg

Insertion of Nanoparticle Clusters into Vesicle Bilayers

Bonnaud, Cécile ; Monnier, Christophe A. ; Demurtas, Davide ; Jud, Corinne ; Vanhecke, Dimitri ; Montet, Xavier ; Hovius, Ruud ; Lattuada, Marco ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: ACS Nano, 2014, vol. 8, no. 4, p. 3451–3460

A major contemporary concern in developing effective liposome–nanoparticle hybrids is the present inclusion size limitation of nanoparticles between vesicle bilayers, which is considered to be around 6.5 nm in diameter. In this article, we present experimental observations backed by theoretical considerations which show that greater structures can be incorporated within vesicle membranes by...

Université de Fribourg

Tracking of fluorescently labeled polymer particles reveals surface effects during shear-controlled aggregation

Caimi, Stefano ; Cingolani, Alberto ; Jaquet, Baptiste ; Siggel, Marc ; Lattuada, Marco ; Morbidelli, Massimo

In: Langmuir, 2017, vol. 33, no. 49, p. 14038–14044

Surface chemistry is believed to be the key parameter affecting the aggregation and breakage of colloidal suspensions when subjected to shear. To date, only a few works dealt with the understanding of the role of the physical and chemical properties of the particles’ surface upon aggregation under shear. Previous studies suggested that surface modifications strongly affect polymer...

Université de Fribourg

Monolithic resorcinol–formaldehyde alcogels and their corresponding nitrogen-doped activated carbons

Civioc, Romain ; Lattuada, Marco ; Koebel, Matthias M. ; Galmarini, Sandra

In: Journal of Sol-Gel Science and Technology, 2020, vol. 95, no. 3, p. 719–732

Here we report the adaptation of formaldehyde crosslinked phenolic resin-based aerogel and xerogel synthesis to ethanol-based solvent systems. Three specific formulations, namely one resorcinol–formaldehyde (RF) and two resorcinol– melamine–formaldehyde (RMF) systems were studied. As-prepared resins were characterized in terms of envelope and skeletal density. Furthermore, resin samples ...

Université de Fribourg

Phase transformation of superparamagnetic iron oxide nanoparticles via thermal annealing: implications for hyperthermia applications

Crippa, Federica ; Rodriguez-Lorenzo, Laura ; Hua, Xiao ; Goris, Bart ; Bals, Sara ; Garitaonandia, José S. ; Balog, Sandor ; Burnand, David ; Hirt, Ann M. ; Haeni, Laetitia ; Lattuada, Marco ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: ACS Applied Nano Materials, 2019, vol. 2, no. 7, p. 4462–4470

Magnetic hyperthermia has the potential to play an important role in cancer therapy and its efficacy relies on the nanomaterials selected. Superparamagnetic iron oxide nanoparticles (SPIONs) are excellent candidates due to the ability of producing enough heat to kill tumor cells by thermal ablation. However, their heating properties depend strongly on crystalline structure and size, which may...

Université de Fribourg

Modeling of the degradation of poly(ethylene glycol)-co-(lactic acid)-dimethacrylate hydrogels

Diederich, Vincent E. G. ; Villiger, Thomas ; Storti, Giuseppe ; Lattuada, Marco

In: Macromolecules, 2017, vol. 50, no. 14, p. 5527–5538

Because of their similarity with extracellular matrix, hydrogels are ideal substrates for cell growth. Hydrogels made of synthetic polymers are excellent alternatives to natural ones and offer the key advantage of precisely controllable degradation times. In this work, hydrogels have been prepared from modified poly(ethylene glycol) macromonomers, functionalized on both ends first with a few...

Université de Fribourg

Magnetic microreactors for efficient and reliable magnetic nanoparticle surface functionalization

Digigow, Reinaldo G. ; Dechézelles, Jean-François ; Kaufmann, J. ; Vanhecke, Dimitri ; Knapp, H. ; Lattuada, Marco ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Lab on a Chip, 2014, p. -

Microreactors have attracted wide attention in the nano- and biotechnology fields because they offer many advantages over standard liquid phase reactions. We report the development of a magnetic microreactor for reliable, fast and efficient surface functionalization of superparamagnetic iron oxide nanoparticles (SPIONs). A comprehensive study of the development process in terms of setup, loading...

Université de Fribourg

Modeling analysis of ultrasonic attenuation and angular scattering measurements of suspended particles

Fleckenstein, Peter ; Storti, Giuseppe ; Deschwanden, Fabian ; Gruber, Peter ; Lattuada, Marco

In: The Journal of the Acoustical Society of America, 2018, vol. 143, no. 2, p. 1049–1063

A combination of two models previously developed by Faran, and Atkinson and Kytömaa (Faran-AK model) was used to calculate the ultrasonic attenuation and the backscattering signal of a suspension of particles. The model of Atkinson and Kytömaa yielded the viscoelastic contributions while the model of Faran yielded the scattering contribution. A comparison with the more fundamental model by...

Université de Fribourg

Triggered metal ion release and oxidation: ferrocene as a mechanophore in polymers

Giannantonio, Michela Di ; Ayer, Mathieu A. ; Verde-Sesto, Ester ; Lattuada, Marco ; Weder, Christoph ; Fromm, Katharina M.

In: Angewandte Chemie International Edition, 2018, vol. 57, no. 35, p. 11445–11450

The introduction of mechanophores into polymers makes it possible to transduce mechanical forces into chemical reactions that can be used to impart functions such as self‐healing, catalytic activity, and mechanochromic response. Here, an example of mechanically induced metal ion release from a polymer is reported. Ferrocene (Fc) was incorporated as an iron ion releasing mechanophore into...

Université de Fribourg

Strong, machinable, and insulating chitosan–urea aerogels: toward ambient pressure drying of biopolymer aerogel monoliths

Guerrero-Alburquerque, Natalia ; Zhao, Shanyu ; Adilien, Nour ; Koebel, Matthias M. ; Lattuada, Marco ; Malfait, Wim J.

In: ACS Applied Materials & Interfaces, 2020, vol. 12, no. 19, p. 22037–22049

Biopolymer aerogels are an emerging class of materials with potential applications in drug delivery, thermal insulation, separation, and filtration. Chitosan is of particular interest as a sustainable, biocompatible, and abundant raw material. Here, we present urea-modified chitosan aerogels with a high surface area and excellent thermal and mechanical properties. The irreversible gelation of...