Université de Fribourg

Precision of Taylor dispersion

Taladriz-Blanco, Patricia ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke ; Balog, Sandor

In: Analytical Chemistry, 2019, vol. 91, no. 15, p. 9946–9951

Taylor dispersion is capable of measuring accurately the hydrodynamic radius over several orders of magnitude. Accordingly, it is now a highly competitive technique dedicated to characterizing small molecules, proteins, macromolecules, nanoparticles, and their self-assembly. Regardless, an in-depth analysis addressing the precision of the technique, being a key indicator of reproducibility,...

Université de Fribourg

Reduction of nanoparticle load in cells by mitosis but not exocytosis

Bourquin, Joël ; Septiadi, Dedy ; Vanhecke, Dimitri ; Balog, Sandor ; Steinmetz, Lukas ; Spuch-Calvar, Miguel ; Taladriz-Blanco, Patricia ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: ACS Nano, 2019, vol. 13, no. 7, p. 7759–7770

The long-term fate of biomedically relevant nanoparticles (NPs) at the single cell level after uptake is not fully understood yet. We report that lysosomal exocytosis of NPs is not a mechanism to reduce the particle load. Biopersistent NPs such as nonporous silica and gold remain in cells for a prolonged time. The only reduction of the intracellular NP number is observed via cell division,...

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

Lock‐in thermography to analyze plasmonic nanoparticle dispersions

Steinmetz, Lukas ; Taladriz‐Blanco, Patricia ; Geers, Christoph ; Spuch‐Calvar, Miguel ; Bonmarin, Mathias ; Balog, Sandor ; Rothen‐Rutishauser, Barbara ; Petri‐Fink, Alke

In: Particle & Particle Systems Characterization, 2019, p. 1900224

The physicochemical properties of nanoparticles (NPs) strongly rely on their colloidal stability, and any given dispersion can display remarkably different features, depending on whether it contains single particles or clusters. Thus, developing efficient experimental methods that are able to provide accurate and reproducible measures of the NP properties is a considerable challenge for both...

Université de Fribourg

Synthesis and properties of poly(norbornene)s with lateral aramid groups

Kong, Phally ; Drechsler, Susanne ; Balog, Sandor ; Schrettl, Stephen ; Weder, Christoph ; Kilbinger, Andreas F. M.

In: Polymer Chemistry, 2019, vol. 10, no. 16, p. 2057–2063

This paper deals with the synthesis and investigation of comb-like poly(norbornene)s carrying lateral rod-like aramid groups. Two types of norbornene-based monomers were synthesized and copolymerized with a norbornene carrying an aliphatic side chain using ring opening metathesis polymerization (ROMP). The new monomers contain aramid derivatives that display different types of non-covalent...

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

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

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

Beyond global charge: role of amine bulkiness and protein fingerprint on nanoparticle–cell interaction

Burnand, David ; Milosevic, Ana ; Balog, Sandor ; Spuch-Calvar, Miguel ; Rothen-Rutishauser, Barbara ; Dengjel, Jörn ; Kinnear, Calum ; Moore, Thomas L. ; Petri-Fink, Alke

In: Small, 2018, vol. 14, no. 46, p. 1802088

Amino groups presented on the surface of nanoparticles are well‐known to be a predominant factor in the formation of the protein corona and subsequent cellular uptake. However, the molecular mechanism underpinning this relationship is poorly defined. This study investigates how amine type and density affect the protein corona and cellular association of gold nanoparticles with cells in...

Université de Fribourg

Hypothesis test of the photon count distribution for dust discrimination in dynamic light scattering

Bossert, David ; Crippa, Federica ; Petri-Fink, Alke ; Balog, Sandor

In: Analytical Chemistry, 2018, vol. 90, no. 6, p. 3656–3660

Users of dynamic light scattering (DLS) are challenged when a sample of nanoparticles (NPs) contains dust. This is a frequently inevitable scenario and a major problem that critically affects the reproducibility and accuracy of DLS measurements. Current methods approach this problem via photon correlation spectroscopy, but remedy exists only for a few special cases. We introduce here a...