Université de Fribourg

A new angle on dynamic depolarized light scattering: number-averaged size distribution of nanoparticles in focus

Geers, Christoph ; Rodriguez-Lorenzo, Laura ; Urban, Dominic Andreas ; Kinnear, Calum ; Petri-Fink, Alke ; Balog, Sandor

In: Nanoscale, 2016, vol. 8, no. 34, p. 15813–15821

Size polydispersity is a common phenomenon that strongly influences the physicochemical properties of nanoparticles (NPs). We present an analytical approach that is universally applicable to characterizing optically anisotropic round NPs and determines directly the number-averaged size distribution and polydispersity via depolarized dynamic light scattering (DDLS). To demonstrate, we use...

Université de Fribourg

Plasmonic nanoparticles and their characterization in physiological fluids

Urban, Dominic A. ; Rodriguez-Lorenzo, Laura ; Balog, Sandor ; Kinnear, Calum ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Colloids and Surfaces B: Biointerfaces, 2016, vol. 137, p. 39–49

Nanoparticles possess unique properties beyond that of classical materials, and while these properties can be used for designing a dedicated functionality, they may also pose a problem to living organisms, to human health and the environment. The specific primary routes by which nanoparticles may interact with the human body include inhalation, injection, ingestion and application to the skin....

Université de Fribourg

An in vitro testing strategy towards mimicking the inhalation of high aspect ratio nanoparticles

Endes, Carola ; Schmid, Otmar ; Kinnear, Calum ; Mueller, Silvana ; Camarero-Espinosa, Sandra ; Vanhecke, Dimitri ; Foster, E. Johan ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara ; Weder, Christoph ; Clift, Martin J.D.

In: Particle and Fibre Toxicology, 2015, vol. 11, no. 1, p. 40

The challenge remains to reliably mimic human exposure to high aspect ratio nanoparticles (HARN) via inhalation. Sophisticated, multi-cellular in vitro models are a particular advantageous solution to this issue, especially when considering the need to provide realistic and efficient alternatives to invasive animal experimentation for HARN hazard assessment. By incorporating a systematic test-bed...

Université de Fribourg

Thermally reversible self-assembly of nanoparticles via polymer crystallization

Kinnear, Calum ; Balog, Sandor ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Macromolecular Rapid Communications, 2014, vol. 35, no. 23, p. 2012–2017

The directed self-assembly of gold nanoparticles through the crystallization of surface-grafted polyethylene oxide (PEO) in ethanol–water mixtures is described. This process is fully reversible and tunable through either the size of the core or the polymeric coating. Characterization by X-ray scattering and electron microscopy of the self-assembled structures reveals order at the nanoscale,...

Université de Fribourg

In Vitro dosimetry of agglomerates

Hirsch, Vera ; Kinnear, Calum ; Rodriguez-Lorenzo, Laura ; Monnier, Christophe A. ; Rothen-Rutishauser, Barbara ; Balog, Sandor ; Petri-Fink, Alke

In: Nanoscale, 2014, p. -

Agglomeration of nanoparticles in biological fluids is a pervasive phenomenon that leads to difficulty in the interpretation of results from in vitro exposures, primarily due to the differing particokinetics of agglomerates to nanoparticles. Therefore, well-defined small agglomerates were designed that possessed different particokinetics profiles, and their cellular uptake was compared to a...

Université de Fribourg

Surface charge of polymer coated SPIONs influences the serum protein adsorption, colloidal stability and subsequent cell interaction in vitro

Hirsch, Vera ; Kinnear, Calum ; Moniatte, Marc ; Rothen-Rutishauser, Barbara ; Clift, Martin J. D. ; Fink, Alke

In: Nanoscale, 2013, vol. 5, no. 9, p. 3723-3732

It is known that the nanoparticle–cell interaction strongly depends on the physicochemical properties of the investigated particles. In addition, medium density and viscosity influence the colloidal behaviour of nanoparticles. Here, we show how nanoparticle–protein interactions are related to the particular physicochemical characteristics of the particles, such as their colloidal stability,...