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Povzetek: Microorganisms in biofilms are protected from environmental stressors and therefore exhibit strong resistance to conventional removal strategies, including chemical disinfectants and antibiotics. In this study, we systematically evaluated nanomaterial-based removal methods on Listeria innocua biofilms. Anisotropic magnetic particles, composed of iron oxide, and silver nanoparticles, known for their intrinsic antibacterial properties, were used to assess the potential of nanostructure-triggered biofilm disruption. We investigated how particle surface roughness and size affect biofilm removal under magnetic actuation, using both classical colony-forming unit quantification (viability assessment) and fluorescence-based detection via a reporter protein. The surface roughness and size of anisotropic magnetic particles only modestly affected biofilm disruption. Conversely, a synergistic effect was observed when anisotropic magnetic particles were grafted with silver nanoparticles. Furthermore, we used Enterococcus faecalis and Candida albicans biofilms and observed pronounced species-dependent variability of the silver-based treatments. Our results indicate that hybrid magneto–chemical strategies represent a promising and likely necessary approach for reliable and robust biofilm removal.
Ključne besede: bacterial biofilm, magnetomechanical detachment, anisotropic magnetic nanoparticles, silver nanoparticles
Objavljeno v DiRROS: 01.07.2026; Ogledov: 102; Prenosov: 101
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Povzetek: Given the growing interest in nanosized spinel-type ferrite nanoparticles for biomedical applications and the limited information on their safety, this study aimed to assess their cellular and genotoxic effects in an in vitro 3D human hepatic cell model (HepG2 spheroids). Ferrite nanoparticles – γFe2O3 (FeNPs; 14 ± 4 nm), Zn0.7Fe2.3O4 (ZnNPs; 14 ± 5 nm), and Mn0.4Fe2.6O4 (MnNPs; 7 ± 2 nm) – were synthesised through a microwave-assisted polyol route, functionalized with citric acid, and characterised using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). Nanoparticle uptake was analysed using TEM, cytotoxicity was measured with CellTiter-Glo®, and oxidative stress induction was assessed using the 2′,7′-Dichlorodihydrofluorescein diacetate (DCFH-DA) and malondialdehyde (MDA) assay. Genotoxic effects were evaluated using the comet, γH2AX and p-H3 assays. Cellular stress responses were assessed using toxicogenomic analysis. Significant cytotoxicity of the tested nanoparticles (0.1–250 µg/mL) was observed; however, TEM analysis revealed limited penetration to the outermost cell layers of spheroids. Notably, only FeNPs induced ROS generation, while MDA levels remained unchanged in all tested samples. Low DNA damage was detected at 24 h, but a significant increase was observed at 96 h (5–50 µg/mL). No increase in γH2AX or p-H3 was found. No substantial alterations in DNA damage or oxidative stress-response gene expression were detected. Altogether, our findings suggest that the effects of ferrite nanoparticles are time- and composition-dependent, underlining the importance of further mechanistic and chronic exposure evaluations in 3D cell models.
Ključne besede: DNA damage, genotoxicity, HepG2 spheroids, magnetic ferrite-based nanoparticles, ROS induction, safety assessment, toxicogenomics
Objavljeno v DiRROS: 27.01.2026; Ogledov: 560; Prenosov: 742
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Povzetek: Biofilms, structured communities of microbial cells embedded in extracellular polymeric substances, are notorious for their resilience against conventional antimicrobial treatments. They contribute significantly to chronic infections and industrial biofouling, necessitating innovative strategies for their eradication. Magnetic iron oxide nanoparticles have emerged as a promising tool in combating biofilms due to their biocompatibility and unique physicochemical properties, which enable magnetic delivery of antibacterial agents, magnetic hyperthermia, magneto-mechanical actuation including mechanical biofilm disruption, and reversible dynamic magnetic assembly into hierarchical structures. This review describes developing stages of magnetic nanoscale weapons against biofilms ranging from individual iron oxide nanoparticles to complex hierarchical nanoparticle assemblies in the form of magnetic robots and their swarms. A vast array of possible antibiofilm and antibacterial functionalities originating from iron ions, individual iron oxide nanoparticles, spherical nanoparticle assemblies, magnetic robots, and swarms of robots are presented. Magnetic nanotools offer significant improvements and advantages over conventional methods for biofilm eradication, yet their successful future applications depend on addressing and overcoming critical material, biological, and engineering challenges.
Ključne besede: biofilm, magnetic nanoparticles, magneto-mechanical actuation, microrobots, nanorobots
Objavljeno v DiRROS: 13.01.2026; Ogledov: 519; Prenosov: 584
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Povzetek: The applications of magnetic nanoparticles (MNPs) as biocatalysts in different biomedical areas have been evolved very recently. One of the main challenges in this field is to design affective MNPs surfaces with catalytically active atomic centres, while producing minimal toxicological side effects on the hosting cell or tissues. MNPs of vanadium spinel ferrite (VFe2O4) are a promising material for mimicking the action of natural enzymes in degrading harmful substrates due to the presence of active V5+ centres. However, the toxicity of this material has not been yet studied in detail enough to grant biomedical safety. In this work, we have extensively measured the structural, compositional, and magnetic properties of a series of VxFe3-xO4 spinel ferrite MNPs to assess the surface composition and oxidation state of V atoms, and also performed systematic and extensive in vitro cytotoxicity and genotoxicity testing required to assess their safety in potential clinical applications. We could establish the presence of V5+ at the particle surface even in water-based colloidal samples at pH 7, as well as different amounts of V2+ and V3+ substitution at the A and B sites of the spinel structure. All samples showed large heating efficiency with Specific Loss Power values up to 400 W/g (H0 = 30 kA/m; f = 700 kHz). Samples analysed for safety in human hepatocellular carcinoma (HepG2) cell line with up to 24h of exposure showed that these MNPs did not induce major genomic abnormalities such as micronuclei, nuclear buds, or nucleoplasmic bridges (MNIs, NBUDs, and NPBs), nor did they cause DNA double-strand breaks (DSBs) or aneugenic effects—types of damage considered most harmful to cellular genetic material. The present study is an essential step towards the use of these type of nanomaterials in any biomedical or clinical application.
Ključne besede: magnetic nanoparticles, vanadium ferrite, cytotoxicity, genotoxicity, specific power absorption, cell viability
Objavljeno v DiRROS: 23.05.2024; Ogledov: 1879; Prenosov: 1090
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