Université de Fribourg

Magneto-responsive cell culture substrates that can be modulated in situ

Crippa, Federica ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 1, p. 51–54

Understanding the interaction between cells and their environment is fundamental for mechanobiology. To mimic the behavior of cells in physiological and pathological conditions, synthetic substrates must have topographical and/or mechanical properties that evolve in time. Dynamic substrates mainly rely on stimuli-responsive materials where an external stimulus induces controlled variations in...

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

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

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

Probing nano-scale viscoelastic response in air and in liquid with dynamic atomic force microscopy

Crippa, Federica ; Thorén, Per-Anders ; Forchheimer, Daniel ; Borgani, Riccardo ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke ; Haviland, David B.

In: Soft Matter, 2018, vol. 14, no. 19, p. 3998–4006

We perform a comparative study of dynamic force measurements using an Atomic Force Microscope (AFM) on the same soft polymer blend samples in both air and liquid environments. Our quantitative analysis starts with calibration of the same cantilever in both environments. Intermodulation AFM (ImAFM) is used to measure dynamic force quadratures on the same sample. We validate the accuracy of the...

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

Nanoparticle–cell interaction: a cell mechanics perspective

Septiadi, Dedy ; Crippa, Federica ; Moore, Thomas Lee ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Advanced Materials, 2018, p. -

Progress in the field of nanoparticles has enabled the rapid development of multiple products and technologies; however, some nanoparticles can pose both a threat to the environment and human health. To enable their safe implementation, a comprehensive knowledge of nanoparticles and their biological interactions is needed. In vitro and in vivo toxicity tests have been considered the gold...

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

Taylor dispersion of nanoparticles

Urban, Dominic A. ; Milosevic, Ana M. ; Crippa, Federica ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Journal of Nanoparticle Research, 2017, vol. 19, no. 8, p. 287

The ability to detect and accurately characterize particles is required by many fields of nanotechnology, including materials science, nanotoxicology, and nanomedicine. Among the most relevant physicochemical properties of nanoparticles, size and the related surface-to-volume ratio are fundamental ones. Taylor dispersion combines three independent phenomena to determine particle size: optical...

Université de Fribourg

Dynamic and biocompatible thermo-responsive magnetic hydrogels that respond to an alternating magnetic field

Crippa, Federica ; Moore, Thomas L. ; Mortato, Mariangela ; Geers, Christoph ; Haeni, Laetitia ; Hirt, Ann M. ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Journal of Magnetism and Magnetic Materials, 2017, vol. 427, p. 212–219

Magnetic thermo-responsive hydrogels are a new class of materials that have recently attracted interest in biomedicine due to their ability to change phase upon magnetic stimulation. They have been used for drug release, magnetic hyperthermia treatment, and can potentially be engineered as stimuli-responsive substrates for cell mechanobiology. In this regard, we propose a series of magnetic...