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

Silver-containing titanium dioxide nanocapsules for combating multidrug-resistant bacteria

Hérault, Nelly ; Wagner, Julia ; Abram, Sarah-Luise ; Widmer, Jérôme ; Horvath, Lenke ; Vanhecke, Dimitri ; Bourquin, Carole ; Fromm, Katharina M

In: International Journal of Nanomedicine, 2020, vol. Volume 15, p. 1267–1281

Background: Joint arthroplasty has improved the quality of life of patients worldwide, but infections of the prosthesis are frequent and cause significant morbidity. Antimicrobial coatings for implants promise to prevent these infections. Methods: We have synthesized nanocapsules of titanium dioxide in amorphous or anatase form containing silver as antibacterial agent and tested their impact ...

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

Carbon nanodots: Opportunities and limitations to study their biodistribution at the human lung epithelial tissue barrier

Durantie, Estelle ; Barosova, Hana ; Drasler, Barbara ; Rodriguez-Lorenzo, Laura ; Urban, Dominic A. ; Vanhecke, Dimitri ; Septiadi, Dedy ; Hirschi-Ackermann, Liliane ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: Biointerphases, 2018, vol. 13, no. 6, p. 06D404

Inhalation of combustion-derived ultrafine particles (≤0.1 μm) has been found to be associated with pulmonary and cardiovascular diseases. However, correlation of the physicochemical properties of carbon-based particles such as surface charge and agglomeration state with adverse health effects has not yet been established, mainly due to limitations related to the detection of carbon...

Université de Fribourg

Assumption-free morphological quantification of single anisotropic nanoparticles and aggregates

Vanhecke, Dimitri ; Rodríguez-Lorenzo, Laura ; Kinnear, Calum ; Durantie, Estelle ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Nanoscale, 2017, vol. 9, no. 15, p. 4918–4927

Characterizing the morphometric parameters of noble metal nanoparticles for sensing and catalysis is a persistent challenge due to their small size and complex shape. Herein, we present an approach to determine the volume, surface area, and curvature of non-symmetric anisotropic nanoparticles using electron tomography and design- based stereology without the use of segmentation tools or...

Université de Fribourg

Synthesis, characterization, antibacterial activity and cytotoxicity of hollow /TiO₂-coated CeO₂ nanocontainers encapsulating silver nanoparticles for controlled silver release

Gagnon, Jacinthe ; Clift, Martin J. D. ; Vanhecke, Dimitri ; Widnersson, I. E. ; Abram, S.-L. ; Petri-Fink, Alke ; Caruso, R. A. ; Rothen-Rutishauser, Barbara ; Fromm, Katharina M.

In: Journal of Materials Chemistry B, 2016, vol. 4, no. 6, p. 1166–1174

Biomaterials as implants are being applied more extensively in medicine due to their on-going development and associated improvements, and the increase in human life expectancy. Nonetheless, biomaterial-related infections, as well as propagating bacterial resistance, remain significant issues. Therefore, there is a growing interest for silver-based drugs because of their efficient and broad-range...

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

Ultrathin ceramic membranes as scaffolds for functional cell coculture models on a biomimetic scale

Jud, Corinne ; Ahmed, Sher ; Müller, Loretta ; Kinnear, Calum ; Vanhecke, Dimitri ; Umehara, Yuki ; Frey, Sabine ; Liley, Martha ; Angeloni, Silvia ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara

In: BioResearch Open Access, 2015, vol. 4, no. 1, p. 457–468

Epithelial tissue serves as an interface between biological compartments. Many in vitro epithelial cell models have been developed as an alternative to animal experiments to answer a range of research questions. These in vitro models are grown on permeable two-chamber systems; however, commercially available, polymer-based cell culture inserts are around 10 μm thick. Since the basement...

Université de Fribourg

A guide to investigating colloidal nanoparticles by cryogenic transmission electron microscopy: pitfalls and benefits

Monnier, Christophe A. ; Thévenaz, David C. ; Balog, Sandor ; Fiore, Gina L. ; Vanhecke, Dimitri ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: AIMS Biophysics, 2015, vol. 2, no. 3, p. 245–258

Synthetic colloidal nanoparticles are nowadays omnipresent. Nonetheless, adequately characterizing them and interpreting the data is challenging, as their surrounding environment, e.g. the medium they are dispersed in, is often an active contributor to their size, morphology and structural integrity. In this regard, cryo-transmission electron microscopy (cryo-TEM) is an ideal methodology. This...

Université de Fribourg

Integrating silver compounds and nanoparticles into ceria nanocontainers for antimicrobial applications

Gagnon, Jacinthe ; Clift, Martin J. D. ; Vanhecke, Dimitri ; Kuhn, Dagmar Alice ; Weber, P. ; Petri-Fink, Alke ; Rothen-Rutishauser, Barbara ; Fromm, Katharina M.

In: Journal of Materials Chemistry B, 2015, vol. 3, no. 9, p. 1760–1768

Silver compounds and nanoparticles (NPs) are gaining increasing interest in medical applications, specifically in the treatment and prevention of biomaterial-related infections. However, the silver release from these materials, resulting in a limited antimicrobial activity, is often difficult to control. In this paper, ceria nanocontainers were synthesized by a template-assisted method and were...