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

Preparation of metallosupramolecular single-chain polymeric nanoparticles and their characterization by Taylor dispersion

Neumann, Laura N. ; Urban, Dominic A. ; Lemal, Philipp ; Ramani, Sushila ; Petri-Fink, Alke ; Balog, Sandor ; Weder, Christoph ; Schrettl, Stephen

In: Polymer Chemistry, 2020, vol. 11, no. 2, p. 586–592

Intramolecular cross-linking of polymers can furnish single-chain polymeric nanoparticles (SCPNs), and the use of reversible non-covalent bonds for cross-linking can potentially provide such nanoparticles with stimuli-responsive properties. Here, we report the synthesis of acrylic polymers that carry pendant 2,6-bis(1′-methyl- benzimidazolyl)pyridine ligands, and use these for the...

Université de Fribourg

Artificial lysosomal platform to study nanoparticle long-term stability

Milosevic, Ana ; Bourquin, Joël ; Burnand, David ; Lemal, Philipp ; Crippa, Federica ; Monnier, Christophe A. ; Rodriguez-Lorenzo, Laura ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 1, p. 55–58

Nanoparticles (NPs) possess unique properties useful for designing specific functionalities for biomedi- cal applications. A prerequisite of a safe-by-design and effective use in any biomedical application is to study NP–cell interactions to gain a better understanding of cellular consequences upon exposure. Cellular uptake of NPs results mainly in the localization of NPs in the complex...

Université de Fribourg

Heating behavior of magnetic iron oxide nanoparticles at clinically relevant concentration

Lemal, Philipp ; Balog, Sandor ; Geers, Christoph ; Taladriz-Blanco, Patricia ; Palumbo, Andrea ; M.Hirt, Ann ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Journal of Magnetism and Magnetic Materials, 2019, vol. 474, p. 637–642

Magnetic hyperthermia for cancer treatment has gained significant attention in recent years, due to its biocompatibility of applied nanoparticles and the possibility for spatially localized heating in deep tissues. Clinical treatments use nanoparticle concentrations of 112 mg Fe/mL, while the concentrations experimental studies have addressed are considerably smaller, usually between 0.1...

Université de Fribourg

Nanoparticles and Taylor dispersion as a linear time-invariant system

Lemal, Philipp ; Petri-Fink, Alke ; Balog, Sandor

In: Analytical Chemistry, 2019, vol. 91, no. 2, p. 1217–1221

The physical principles underpinning Taylor dispersion offer a high dynamic range to characterize the hydrodynamic radius of particles. While Taylor dispersion grants the ability to measure radius within nearly 5 orders of magnitude, the detection of particles is never instantaneous. It requires a finite sample volume, a finite detector area, and a finite detection time for measuring...

Université de Fribourg

Lock-in thermography as a rapid and reproducible thermal characterization method for magnetic nanoparticles

Lemal, Philipp ; Geers, Christoph ; Monnier, Christophe A. ; Crippa, Federica ; Daum, Leopold ; Urban, Dominic A. ; Rothen-Rutishauser, Barbara ; Bonmarin, Mathias ; Petri-Fink, Alke

In: Journal of Magnetism and Magnetic Materials, 2017, vol. 427, p. 206–211

Lock-in thermography (LIT) is a sensitive imaging technique generally used in engineering and materials science (e.g. detecting defects in composite materials). However, it has recently been expanded for investigating the heating power of nanomaterials, such as superparamagnetic iron oxide nanoparticles (SPIONs). Here we implement LIT as a rapid and reproducible method that can evaluate the...