Recherche

Milosevic Irena

Professeure HES associée

Compétences principales

Functional Surfaces and Materials

Professeure HES associée

Bureau: A203a

Haute école du paysage, d'ingénierie et d'architecture de Genève
Rue de la Prairie 4, 1202 Genève, CH

Domaine
Technique et IT

Filière principale
Génie mécanique

BSc HES-SO en Génie mécanique - Haute école du paysage, d'ingénierie et d'architecture de Genève

Science des matériaux

En cours

INTOX

Rôle: Collaborateur/trice

Financement: HES

Description du projet :

Nanotechnologies refer to technologies which exploit the unique properties of tiny particles of nanometre size (millionths of a millimetre), called nanoparticles (NPs). The NPs represent a fast-growing market. In fact, they are already being used in a variety of technologies and consumer products. Their attractive physicochemical properties for improving food taste and texture, increasing nutrient bioavailability, or their antimicrobial properties make them widely used in the food industry. For example, E151 and E171 are additives commonly used in food industry and refer respectively to SiO2 and TiO2 NPs. They are present in a lot of products and even in drugs. Many studies have shown that cellular or organ damage can occur in various places within the gastrointestinal tract, as well as after absorption of the NPs into the body. The role of the overproduction of reactive oxygen species was pointed out to be a key factor in NPs-induced toxicity. Nevertheless, no clear correlation nor study established the influence of the physicochemical properties of NPs and the Reactive oxygen species-induced cytotoxicity.

In this project, three kinds of NPs which are commonly used in food industry, will be produced with controlled properties : AgNPs, TiO2 NPs and SiO2 NPs. Moreover, detailed both chemical and physical characterisation of these NPs will be performed.

Afterwards, in order to assess their cytotoxic effect especially the one associated with ROS production in cells, in this project we will investigate the influence of key parameters related to NPs on cell viability. Such key parameters are for instance : the specific surface area, the presence of a surface coating (naked vs coated NPs) and the cristallinity (amorphous vs crystalline) of the NPs. In that purpose, a first screening will be done using uptake and cytotoxicity of the NPs in vitro on cell. The cytotoxicity associated with reactive oxygen species (ROS) generation will be highlighted in this study. Finally, Caenorhabditis elegans (C. elegans), an alternative in vivo model, will be used to test systemic response on an organism and the fate of ingested NPs.

The aim of this project is build a toolbox to predict NP-induced toxicity by discriminating the influence of different key parameters.

Equipe de recherche au sein de la HES-SO: Milosevic Irena

Durée du projet: 01.09.2020

Montant global du projet: 110'000 CHF

Statut: En cours

Innocem - Determination of scale-up parameters

Rôle: Collaborateur/trice

Requérant(e)s: Abhishek Kumar, Nanogence - Renens

Financement: GRS foundation

Description du projet :

The project is to determine the right operating conditions for the production machine to manufacture the tailored nanoparticle additives for the application in the construction sector.

The operating conditions are varied depending on the prior experience and calculation based on the lab production parameters. Different batches of the products are produced with variable parameters and material produced are analyzed with different analytical equipment and co-relation is developed between operating parameters and quality of the material.

Equipe de recherche au sein de la HES-SO: Milosevic Irena

Durée du projet: 01.08.2020

Montant global du projet: 220'000 CHF

Statut: En cours

Bactericidal nanoblades

Rôle: Collaborateur/trice

Requérant(e)s: Stane Pajk, University of Ljubljana, Slovénie

Financement: FNS

Description du projet :

Les biofilms offrent aux bactéries un bouclier mécanique protecteur et un milieu très favorable à leur développement et prolifération sur des surfaces. L’éradication des biofilms bactériens est devenue un enjeu primordial dans les domaines de la santé, de l'industrie agroalimentaire, l'approvisionnement en eau, les systèmes de ventilation et de traitement de l’air. Ainsi, il est primordial de trouver des solutions efficaces afin d’éradiquer les biofilms persistants. L'objectif principal de notre projet est de valider la faisabilité du concept des nanoblades bactéricides permettant l'élimination de biofilms de manière chimio-mécanique bimodale. Différents protocoles seront testés afin d’évaluer la performance de notre concept qui combine, en synergie, une action de destruction mécanique et une action bactéricide. La destruction mécanique se fera par la conversion de l'énergie magnétique en un mouvement de rotation de particules magnétiques anisotropes (facteur de forme) contrôlées à distance. La composante bactéricide sera fournie par la libération d'ions argent, générant un environnement antimicrobien à large spectre. Cette stratégie sera évaluée sur différentes combinaisons de biofilms bactériens et surfaces, y compris des bactéries très importantes pour le système de santé et l'industrie alimentaire. Le projet contient de nombreuses approches méthodologiques innovantes et ambitieuses nécessitant une expertise interdisciplinaire. La confirmation de l’approche chimio-mécanique peut avoir un impact énorme sur la santé publique car ce nouveau concept pourrait changer le paradigme de la lutte contre les biofilms dans l'industrie alimentaire et le système de santé.

Equipe de recherche au sein de la HES-SO: Milosevic Irena

Partenaires académiques: Stane Pajk, University of Ljubljana, Slovénie

Montant global du projet: 481'335 CHF

Statut: En cours

2022

Magnetic properties, phase evolution, hollow structure and biomedical application of hematite (a-Fe2O3) and QUAIPH

Article scientifique ArODES

Marin Tadic, Matjaz Panjan, Yoann Lalatone, Irena Milosevic, Biljana Vucetic Tadic, Jelena Lazovic

Advanced Powder Technology, 2022, vol. 33, no. 12, article no. 103847

Lien vers la publication

Résumé:

We investigate synthesis, phase evolution, hollow and porous structure and magnetic properties of quasi-amorphous intermediate phase (QUAIPH) and hematite (α-Fe2O3) nanostructure synthesized by annealing of akaganeite (β-FeOOH) nanorods. It is found that the annealing temperature determines the phase composition of the products, the crystal structure/size dictates the magnetic properties whereas the final nanorod morphology is determined by the starting material. Annealing of β-FeOOH at ∼300 °C resulted in the formation of hollow QUAIPH nanorods. The synthesized material shows low-cytotoxicity, superparamagnetism and good transverse relaxivity, which is rarely reported for QUAIPH. The QUAIPH nanorods started to transform to porous hematite nanostructures at ∼350 °C and phase transformation was completed at 600 °C. During the annealing, the crystal structure changed from monoclinic (akaganeite) to quasi-amorphous and rhombohedral (hematite). Unusually, the crystallite size first decreased (akaganeite → QUAIPH) and then increased (QUAIPH → hematite) during annealing whereas the nanorods retained particle shape. The magnetic properties of the samples changed from antiferromagnetic (akaganeite) to superparamagnetic with blocking temperature TB = 84 K (QUAIPH) and finally to weak-ferromagnetic with the Morin transition at TM = 244 K and high coercivity HC = 1652 Oe (hematite). The low-cytotoxicity and MRI relaxivity (r2 = 5.80 mM−1 s−1 (akaganeite), r2 = 4.31 mM−1 s−1 (QUAIPH) and r2 = 5.17 mM−1 s−1 (hematite)) reveal potential for biomedical applications.

Poly(methyl methacrylate) with oleic acid as an efficient candida albicans biofilm repellent

Article scientifique ArODES

Milica Petrovic, Marina Randjelovic, Marko Igic, Milica Randjelovic, Valentina Arsic Arsenijevic, Marijiana Mionic Ebersold, Suzana Otasevic, Irena Milosevic

Materials, 2022, vol. 15, no. 11, article no. 3750

Lien vers la publication

Résumé:

Poly(methyl methacrylate) (PMMA), widely used in dentistry, is unfortunately a suitable substrate for Candida (C.) albicans colonization and biofilm formation. The key step for biofilm formation is C. albicans ability to transit from yeast to hypha (filamentation). Since oleic acid (OA), a natural compound, prevents filamentation, we modified PMMA with OA aiming the antifungal PMMA_OA materials. Physico-chemical properties of the novel PMMA_OA composites obtained by incorporation of 3%, 6%, 9%, and 12% OA into PMMA were characterized by Fourier-transform infrared spectroscopy and water contact angle measurement. To test antifungal activity, PMMA_OA composites were incubated with C. albicans and the metabolic activity of both biofilm and planktonic cells was measured with a XTT test, 0 and 6 days after composites preparation. The effect of OA on C. albicans morphology was observed after 24 h and 48 h incubation in agar loaded with 0.0125% and 0.4% OA. The results show that increase of OA significantly decreased water contact angle. Metabolic activity of both biofilm and planktonic cells were significantly decreased in the both time points. Therefore, modification of PMMA with OA is a promising strategy to reduce C. albicans biofilm formation on denture.

Réalisations

Recherche

Milosevic Irena

Professeure HES associée

Compétences principales

Nanoparticle synthesis

Nanotechnology

Materials characterization

Functional Surfaces and Materials

Material sciences

Nanocomposites & Nanofibers

Professeure HES associée