Université de Fribourg

Trithiocarbonate-functionalized PNiPAAm-based nanocomposites for antimicrobial properties

Tan, Milène ; Horvàth, Lenke ; Brunetto, Priscilla S. ; Fromm, Katharina M.

In: Polymers, 2018, vol. 10, no. 6, p. 665

In this study, four trithiocarbonate-functionalized PNiPAAms with different molecular weights were synthesized and used as a matrix to form composites with silver nanoparticles. Nanocomposites with several polymer-to-silver ratios P:Ag+ were prepared in order to evaluate the influence of silver loading. UV studies showed a thermoresponsive behavior of the nanocomposites with a...

Université de Fribourg

Antimicrobial silver-filled silica nanorattles with low immunotoxicity in dendritic cells

Priebe, Magdalena ; Widmer, Jérôme ; Löwa, Nina Suhartha ; Abram, Sarah-Luise ; Mottas, Inès ; Woischnig, Anne-Kathrin ; Brunetto, Priscilla S. ; Khanna, Nina ; Bourquin, Carole ; Fromm, Katharina M.

In: Nanomedicine: Nanotechnology, Biology and Medicine, 2017, vol. 13, no. 1, p. 11–22

The progression in the use of orthopedic implants has led to an increase in the absolute number of implant infections, triggering a search for more effective antibacterial coatings. Nanorattles have recently gained interest in biomedical applications such as drug delivery, as encapsulation of the cargo inside the hollow structure provides a physical protection from the surrounding...

Université de Fribourg

Synthesis of new polyether ether ketone derivatives with silver binding site and coordination compounds of their monomers with different silver salts

Girard, Jérôme ; Joset, Nathalie ; Crochet, Aurélien ; Tan, Milène ; Holzheu, Anja ; Brunetto, Priscilla S. ; Fromm, Katharina M.

In: Polymers, 2016, vol. 8, no. 6, p. 208

Polyether ether ketone (PEEK) is a well-known polymer used for implants and devices, especially spinal ones. To overcome the biomaterial related infection risks, 4-4′- difluorobenzophenone, the famous PEEK monomer, was modified in order to introduce binding sites for silver ions, which are well known for their antimicrobial activity. The complexation of these new monomers with different...

Université de Fribourg

Preventing implant-associated infections by silver coating

Kuehl, Richard ; Brunetto, Priscilla S. ; Woischnig, Anne-Kathrin ; Varisco, Massimo ; Rajacic, Zarko ; Vosbeck, Juerg ; Terracciano, Luigi ; Fromm, Katharina M. ; Khanna, Nina

In: Antimicrobial Agents and Chemotherapy, 2016, p. AAC.02934–15

Implant-associated infections (IAI) are a dreaded complication mainly caused by biofilm-forming staphylococci. Implant surfaces preventing microbial colonization would be desirable. We examined the preventive effect of a silver-coated titanium aluminium niobium (TiAlNb) alloy. The surface elicited a strong, inoculum-dependent activity against Staphylococcus (S.) epidermidis and S. aureus in an...

Université de Fribourg

Development of a polystyrene sulfonate/silver nanocomposite with self-healing properties for biomaterial applications

Girard, Jérôme ; Brunetto, Priscilla S. ; Braissant, Olivier ; Rajacic, Zarko ; Khanna, Nina ; Landmann, Regine ; Daniels, Alma U. ; Fromm, Katharina M.

In: Comptes Rendus Chimie, 2013, vol. 16, no. 6, p. 550–556

A silver polystyrene sulfonate polyelectrolyte was synthesized, showing a spontaneous reduction of silver ions to silver nanoparticles over a period of approximately 1 month. A follow-up of the nanoparticle formation via scanning electron microscopy (SEM) reveals migration of the nanoparticles towards the cracks of the polymer over time, leading to a self-healing process of the nanocomposite....

Université de Fribourg

Rings, chains and helices: new antimicrobial silver coordination compounds with (iso-)nicotinic acid derivatives

Chevrier, Inès ; Sagué, Jorge L. ; Brunetto, Priscilla S. ; Khanna, Nina ; Rajacic, Zarko ; Fromm, Katharina M.

In: Dalton Transactions, 2013, vol. 42, no. 1, p. 217-231

Complexes with silver ions have great potential for applications in medicine. Appropriate bidentate ligands, binding to silver ions, are able to generate coordination polymers as well as molecular entities as a function of ligand flexibility, conformation and length. Here we present the continuation of our previous studies in this field with ligands based on oligomers of polyethylene glycol,...

Université de Fribourg

In vitro biocompatibility of new silver(I) coordination compound coated-surfaces for dental implant applications

Brunetto, Priscilla S. ; Slenters, Tünde Vig ; Fromm, Katharina M.

In: Materials, 2011, vol. 4, no. 2, p. 355-367

Biofilm formation on implant materials causes a common problem: resistance to aggressive pharmacological agents as well as host defenses. Therefore, to reduce bacterial adhesion to implant surfaces we propose to use silver(I) coordination networks as it is known that silver is the most powerful antimicrobial inorganic agent. As a model surface, self-assembled monolayers (SAMs) on gold Au(111) was...

Université de Fribourg

Silver coordination polymers for prevention of implant infection: thiol interaction, impact on respiratory chain enzymes, and hydroxyl radical induction

Gordon, Oliver ; Slenters, Tünde Vig ; Brunetto, Priscilla S. ; Villaruz, Amer E. ; Sturdevant, Daniel E. ; Otto, Michael ; Landmann, Regine ; Fromm, Katharina M.

In: Antimicrobial Agents and Chemotherapy, 2010, vol. 54, no. 10, p. 4208-4218

Prosthetic joint replacements are used increasingly to alleviate pain and improve mobility of the progressively older and more obese population. Implant infection occurs in about 5% of patients and entails significant morbidity and high social costs. It is most often caused by staphylococci, which are introduced perioperatively. They are a source of prolonged seeding and difficult to treat...

Université de Fribourg

Of chains and rings: synthetic strategies and theoretical investigations for tuning the structure of silver coordination compounds and their applications

Slenters, Tünde Vig ; Sagué, Jorge L. ; Brunetto, Priscilla S. ; Zuber, Stefanie ; Fleury, Antoine ; Mirolo, Laurent ; Robin, Adeline Y. ; Meuwly, Markus ; Gordon, Oliver ; Landmann, Regine ; Daniels, Alma U. ; Fromm, Katharina M.

In: Materials, 2010, vol. 3, no. 5, p. 3407-3429

Varying the polyethyleneglycol spacer between two (iso)-nicotinic groups of the ligand systems, a large structural variety of silver coordination compounds was obtained, starting with zero-dimensional ring systems, via one-dimensional chains, helices and double-helices to two-dimensional polycatenanes. Theoretical calculations help to understand their formation and allow predictions in some...