Université de Fribourg

Shear stress-responsive polymersome nanoreactors inspired by the marine bioluminescence of dinoflagellates

Rifaie‐Graham, Omar ; Galensowske, Nikolas F. B. ; Dean, Charlie ; Pollard, Jonas ; Balog, Sandor ; Gouveia, Micael G. ; Chami, Mohamed ; Vian, Antoine ; Amstad, Esther ; Lattuada, Marco ; Bruns, Nico

In: Angewandte Chemie International Edition, 2020, vol. 60, no. 2, p. 904-909

Some marine plankton called dinoflagellates emit light in response to the movement of surrounding water, resulting in a phenomenon called milky seas or sea sparkle. The underlying concept, a shear-stress induced permeabilisation of biocatalytic reaction compartments, is transferred to polymer-based nanoreactors. Amphiphilic block copolymers that carry nucleobases in their hydrophobic block...

Université de Fribourg

Simple and fast evaluation of relaxation parameters of magnetic nanoparticles

Lemal, Philipp ; Balog, Sandor ; Ackermann-Hirschi, Liliane ; Taladriz-Blanco, Patricia ; Hirt, Ann M. ; Rothen-Rutishauser, Barbara ; Lattuada, Marco ; Petri-Fink, Alke

In: Journal of Magnetism and Magnetic Materials, 2020, vol. 499, p. 166176

The efficacy of magnetic hyperthermia treatment depends on the optimal available magnetic nanoparticles (MNPs) that are excited in a given alternating magnetic field and viscosity of the region of interest. In this regard, assessing the relevant relaxation parameters is of upmost importance and could improve the speed of development of efficient applications. Here, we demonstrate how to...

Université de Fribourg

Functional polymers through mechanochemistry

Schrettl, Stephen ; Balkenendea, Diederik W. R. ; Calvino, Céline ; Karman, Marc ; Lavrenova, Anna ; Neumann, Laura N. ; Sagaraa, Yoshimitsu ; Verde-Sestoa, Ester ; Giannantonio, Michela di ; Simon, Yoan C. ; Fromm, Katharina M. ; Lattuada, Marco ; Weder, Christoph

In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 1, p. 7–11

While coupling mechanical and chemical processes is widespread in living organisms, the idea to harness the mechanically induced dissociation of weak covalent and non- covalent bonds to create artificial materials that respond to mechanical stimulation has only recently gained attention. Here we summarize our activities that mainly revolve around the exploitation of non-covalent interactions...

Université de Fribourg

Nanoparticle administration method in cell culture alters particle-cell interaction

Moore, Thomas L. ; Urban, Dominic A. ; Rodriguez-Lorenzo, Laura ; Milosevic, Ana ; Crippa, Federica ; Spuch-Calvar, Miguel ; Balog, Sandor ; Rothen-Rutishauser, Barbara ; Lattuada, Marco ; Petri-Fink, Alke

In: Scientific Reports, 2019, vol. 9, no. 1, p. 900

As a highly interdisciplinary field, working with nanoparticles in a biomedical context requires a robust understanding of soft matter physics, colloidal behaviors, nano- characterization methods, biology, and bio-nano interactions. When reporting results, it can be easy to overlook simple, seemingly trivial experimental details. In this context, we set out to understand how in vitro...

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

Lock-in thermography as an analytical tool for magnetic nanoparticles: measuring heating power and magnetic fields

Monnier, Christophe A. ; Crippa, Federica ; Geers, Christoph ; Knapp, Evelyne ; Rothen-Rutishauser, Barbara ; Bonmarin, Mathias ; Lattuada, Marco ; Petri-Fink, Alke

In: The Journal of Physical Chemistry C, 2017, vol. 121, no. 48, p. 27164–27175

Magnetic nanoparticles and their ability to convert electromagnetic energy into heat are of explicit interest for various applications. However, precise quantification of their heating efficiency is not always upfront, and several parameters render comparative studies challenging. This paper describes the theory behind lock-in thermography, a new technique for quantifying the heating...

Université de Fribourg

Effect of aging on silica aerogel properties

Iswar, Subramaniam ; Malfait, Wim J. ; Balog, , Sandor ; Winnefeld, Frank ; Lattuada, Marco ; Koebel, Matthias M.

In: Microporous and Mesoporous Materials, 2017, vol. 241, p. 293–302

Silica aerogels’ unique physical and chemical properties make them fascinating materials for a wide variety of applications. In addition to hydrophobization by silylation, aging is very important in the synthesis of silica aerogel by ambient pressure drying. Here we systematically study the effect of aging on the physico-chemical properties of silica aerogel with emphasis on ambient dried...

Université de Fribourg

A lock-in-based method to examine the thermal signatures of magnetic nanoparticles in the liquid, solid and aggregated states

Monnier, Christophe A. ; Lattuada, Marco ; Burnand, David ; Crippa, F. ; Martinez-Garcia, J. C. ; Hirt, A. M. ; Rothen-Rutishauser, B. ; Bonmarin, M. ; Petri-Fink, Alke

In: Nanoscale, 2016, vol. 8, no. 27, p. 13321–13332

We propose a new methodology based on lock-in thermography to study and quantify the heating power of magnetic nanoparticles. Superparamagnetic iron oxide nanoparticles exposed to a modulated alternating magnetic field were used as model materials to demonstrate the potency of the system. Both quantitative and qualitative information on their respective heating power was extracted at high...

Université de Fribourg

The role of mass and length in the sonochemistry of polymers

Schaefer, Mark ; Icli, Burcak ; Weder, Christoph ; Lattuada, Marco ; Kilbinger, Andreas F. M. ; Simon, Yoan C.

In: Macromolecules, 2016, vol. 49, no. 5, p. 1630–1636

The ultrasound-induced cleavage of macromolecules has become a routine experiment in the emerging field of polymer mechanochemistry. To date, it has not been conclusively proven whether the molecular weight of a polymer or its contour length is the determining factor for chain scission upon ultrasonication. Here we report comparative experiments that confirm unequivocally that the contour length...

Université de Fribourg

Nanoparticle colloidal stability in cell culture media and impact on cellular interactions

Moore, Thomas L. ; Rodriguez-Lorenzo, Laura ; Hirsch, Vera ; Balog, Sandor ; Urban, Dominic ; Jud, Corinne ; Rothen-Rutishauser, Barbara ; Lattuada, Marco ; Petri-Fink, Alke

In: Chemical Society Reviews, 2015, vol. 44, no. 17, p. 6287–6305

Nanomaterials are finding increasing use for biomedical applications such as imaging, diagnostics, and drug delivery. While it is well understood that nanoparticle (NP) physico-chemical properties can dictate biological responses and interactions, it has been difficult to outline a unifying framework to directly link NP properties to expected in vitro and in vivo outcomes. When introduced to...