Université de Fribourg

Characterization of the shape anisotropy of superparamagnetic iron oxide nanoparticles during thermal decomposition

Vanhecke, Dimitri ; Crippa, Federica ; Lattuada, Marco ; Balog, Sandor ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Materials, 2020, vol. 13, no. 9, p. 2018

Magnetosomes are near-perfect intracellular magnetite nanocrystals found in magnetotactic bacteria. Their synthetic imitation, known as superparamagnetic iron oxide nanoparticles (SPIONs), have found applications in a variety of (nano)medicinal fields such as magnetic resonance imaging contrast agents, multimodal imaging and drug carriers. In order to perform these functions in medicine,...

Université de Fribourg

Quantifying nanoparticle cellular uptake: which method is best?

Drasler, Barbara ; Vanhecke, Dimitri ; Rodriguez-Lorenzo, Laura ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: Nanomedicine, 2017, vol. 12, no. 10, p. 1095–1099

As the range of engineered nanoparticles (NPs) designed as specific carriers increases, for example for cell targeting and drug delivery, the question on how many NPs are interacting or are taken up by cells is becoming increasingly important for any potential biomedical application. On one hand, the delivered dose of such NPs to the targeted cells is a key parameter in the assessment of...

Université de Fribourg

A novel technique to determine the cell type specific response within an in vitro co-culture model via multi-colour flow cytometry

Clift, Martin J. D. ; Fytianos, Kleanthis ; Vanhecke, Dimitri ; Hočevar, Sandra ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: Scientific Reports, 2017, vol. 7, no. 1, p. 434

Determination of the cell type specific response is essential towards understanding the cellular mechanisms associated with disease states as well as assessing cell-based targeting of effective therapeutic agents. Recently, there have been increased calls for advanced in vitro multi-cellular models that provide reliable and valuable tools correlative to in vivo. In this pursuit the ability to...

Université de Fribourg

Formation of drug nanocrystals under nanoconfinement afforded by liposomes

Cipolla, D. ; Wu, H. ; Salentinig, S. ; Boyd, B. ; Rades, T. ; Vanhecke, Dimitri ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara ; Eastman, S. ; Redelmeier, T. ; Gonda, I. ; Chan, H. K.

In: RSC Advances, 2016, vol. 6, no. 8, p. 6223–6233

Nanocrystals of drug substances have important therapeutic applications, but their preparation is often difficult due to size control in bottom up approaches, or energetic milling and surface activation in top down processing. In this study, confinement within liposome nanocompartments is demonstrated to enable drug crystallization with a high aspect ratio but limited growth resulting in...

Université de Fribourg

Avoiding drying-artifacts in transmission electron microscopy: Characterizing the size and colloidal state of nanoparticles

Michen, Benjamin ; Geers, Christoph ; Vanhecke, Dimitri ; Endes, Carola ; Rothen-Rutishauser, Barbara ; Balog, Sandor ; Petri-Fink, Alke

In: Scientific Reports, 2015, vol. 5, p. 9793

Standard transmission electron microscopy nanoparticle sample preparation generally requires the complete removal of the suspending liquid. Drying often introduces artifacts, which can obscure the state of the dispersion prior to drying and preclude automated image analysis typically used to obtain number-weighted particle size distribution. Here we present a straightforward protocol for...

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

Modeling nanoparticle–alveolar epithelial cell interactions under breathing conditions using captive bubble surfactometry

Schürch, David ; Vanhecke, Dimitri ; Clift, Martin J. D. ; Raemy, David ; Aberasturi, Dorleta Jimenez de ; Parak, Wolfgang J. ; Gehr, Peter ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: Langmuir, 2014, vol. 30, no. 17, p. 4924–4932

Many advances have been made in recent years in cell culture models of the epithelial barrier of the lung from simple monolayers to complex 3-D systems employing different cell types. However, the vast majority of these models still present a static air–liquid interface which is unrealistic given the dynamic nature of breathing. We present here a method where epithelial lung cells are...

Université de Fribourg

Spatial SPION localization in liposome membranes

Bonnaud, Cécile ; Vanhecke, Dimitri ; Demurtas, Davide ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: IEEE Transactions on Magnetics, 2012, vol. 49, no. 1, p. 166-171

Nanocarriers, including liposomes, offer great opportunities for targeted and controlled therapy. The development in this field has led to a large panel of drug delivery systems, which can be classified into 3 different nanovector generations. However, the success of such smart materials requires the control of a large variety of properties and parameters. Unfortunately, characterization at the...