Université de Fribourg

Taylor dispersion of inorganic nanoparticles and comparison to dynamic light scattering and transmission electron microscopy

A.Urban, Dominic ; M.Milosevic, Ana ; Bossert, David ; Crippa, Federica ; L.Moore, Thomas ; Geers, Christoph ; Balog, Sandor ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Colloid and Interface Science Communications, 2018, vol. 22, p. 29–33

Taylor dispersion analysis (TDA) is an analytical method that has so far mainly been utilized to determine the diffusion coefficient of small molecules, and proteins. Due to increasing interest in nanoscience, some research has been done on the applicability of TDA towards characterizing nanoparticles. This work aims to expand this knowledge and give insight into the range for which TDA can...

Université de Fribourg

Mechanochemistry with Metallosupramolecular Polymers

Balkenende, Diederik W. R. ; Coulibaly, Souleymane ; Balog, Sandor ; Simon, Yoan C. ; Fiore, Gina L. ; Weder, Christoph

In: Journal of the American Chemical Society, 2014, vol. 136, no. 29, p. 10493-10498

The transduction of mechanical force into useful chemical reactions is an emerging design approach to impart soft materials with new functions. Here, we report that mechanochemical transductions can be achieved in metallo-supramolecular polymers. We show that both reversible and irreversible reactions are possible and useful to create me-chanically responsive materials that display new...

Université de Fribourg

Dynamic depolarized light scattering of small round plasmonic nanoparticles: When imperfection is only perfect

Balog, Sandor ; Adolphe Merkle Institute, University of Fribourg, Switzerland ; Rodriguez-Lorenzo, Laura ; Monnier, Christophe A. ; Michen, Benjamin ; Obiols-Rabasa, Marc ; Casal-Dujat, Lucia ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke ; Schurtenberger, and Peter

In: The Journal of Physical Chemistry C, 2014, vol. 118, no. 31, p. 17968–17974

Although small round gold nanoparticles (Au NPs) possess only a small degree of shape anisotropy, they support localized surface plasmon resonances and exhibit intrinsic optical anisotropy. These inherent features promote depolarized light scattering, whose temporal fluctuations carry information about rotational Brownian dynamics, and thus can be used to describe the size distribution of round...

Université de Fribourg

Use of EpiAlveolar lung model to predict fibrotic potential of multiwalled carbon nanotubes

Barosova, Hana ; Maione, Anna G. ; Septiadi, Dedy ; Sharma, Monita ; Haeni, Laetitia ; Balog, Sandor ; O’Connell, Olivia ; Jackson, George R. ; Brown, David ; Clippinger, Amy J. ; Hayden, Patrick ; Petri-Fink, Alke ; Stone, Vicki ; Rothen-Rutishauser, Barbara

In: ACS Nano, 2020, vol. 14, no. 4, p. 3941–3956

Expansion in production and commercial use of nanomaterials increases the potential human exposure during the lifecycle of these materials (production, use, and disposal). Inhalation is a primary route of exposure to nanomaterials; therefore it is critical to assess their potential respiratory hazard. Herein, we developed a three-dimensional alveolar model (EpiAlveolar) consisting of human...

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...

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

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

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

The influence of substituents on gelation and stacking order of oligoaramid – based supramolecular networks

Drechsler, Susanne ; Balog, Sandor ; Kilbinger, Andreas F. M. ; Casalini, Tommaso

In: Soft Matter, 2019, vol. 15, no. 36, p. 7250–7261

Self-assembly has proven to be a powerful tool for functional, smart materials such as hydrogels derived from low molecular weight compounds. However, the targeted design of functional gelators remains difficult. Here, we present a set of four Y-shaped aromatic amide tetramers with varying functionalities able to undergo different non- covalent interactions. These compounds were explored...