Magnetite (FeO) nanoparticles (NPs) have widely used in various fields, including in medicine, due to their (super)paramagnetic properties. This requires a thorough evaluation of their possible hazardous effects. However, there is no standard procedure for the preparation of oxidation-prone NPs (such as magnetite) before subjecting them to biological assays. In this study we used FeO NPs (bare and silica-coated) as test samples to compare different preparation methods (ultrasound, centrifugation and filteration of NPs suspensions) based on X-ray and dynamic light scattering analysis and evaluation of microstructure and surface charge. After oxidation and functionalization, all samples retained their superparamagnetic behaviour. The toxicity of NP suspensions obtained by the methods described for ciliates and plants was evaluated.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9042031 | PMC |
http://dx.doi.org/10.1039/d1ra05703k | DOI Listing |
ACS Nano
February 2024
Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
While metal nanoparticles are widely used, their small size makes them mechanically unstable. Extensive prior research has demonstrated that nanoparticles with sizes in the range of 10-50 nm fail by the surface nucleation of dislocations, which is a thermally activated process. Two different contributions have been suggested to cause the weakening of smaller particles: first, geometric effects such as increased surface curvature reduce the barrier for dislocation nucleation; second, surface diffusion happens faster on smaller particles, thus accelerating the formation of surface kinks which nucleate dislocations.
View Article and Find Full Text PDFACS Omega
November 2023
Department of Chemistry, University of California, Davis, California 95616, United States.
Gold nanostructures were synthesized by etching away gold from heat-treated mesoporous silica-coated gold nanorods (AuNR@mSiO), providing an example of top-down modification of nanostructures made using bottom-up methodology. Twelve different types of nanostructures were made using this ottom-p-hen-p-dowynthesis (BUTTONS), of which the etching of the same starting nanomaterial of AuNR@mSiO was found to be controlled by how AuNR@mSiO were heat treated, the etchant concentration, and etching time. When the heat treatment occurred in smooth moving solutions in round-bottomed flasks, red-shifted longitudinal surface plasmon resonance (LSPR) was observed, on the order of 10-30 min, indicating increased aspect ratios of the gold nanostructures inside the mesoporous silica shells.
View Article and Find Full Text PDFSemiconductor photocatalysts are promising cost-effective materials for degrading hazardous organic contaminants in water. AgPO is an efficient visible-light photocatalyst for the oxidation of water and dye degradation. The excited AgPO photocatalyst uses a hole to oxidise water or organic contaminants except the electron, which reduces Ag to Ag.
View Article and Find Full Text PDFHeliyon
August 2023
Centre for Interdisciplinary Research, D.Y. Patil Educational Society, Kolhapur, India.
Yolk-shell-based silica-coated silver nanoparticles are prominently used in the biomedical field aas well as bare silver nanoparticles for various biological applications. The present work narrates the synthesis and silica coating of metallic silver nanoparticles and investigates their antibacterial, antifungal, and anticancerous activity. Both synthesized nanoparticles were characterized by TEM, and SEM-EDX.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
August 2023
Chair of Bioseparation Engineering, TUM School of Engineering and Design, Technical University of Munich, Boltzmannstraße 15, 85748 Garching, Germany; Division of Medicinal Chemistry, Otto Loewi Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010 Graz, Austria; BioTechMed, Mozartgasse 12, 8010 Graz, Austria. Electronic address:
Coated iron oxide nanoparticles (IONs) are promising candidates for various applications in nanomedicine, including imaging, magnetic hyperthermia, and drug delivery. The application of IONs in nanomedicine is influenced by factors such as biocompatibility, surface properties, agglomeration, degradation behavior, and thrombogenicity. Therefore, it is essential to investigate the effects of coating material and thickness on the behavior and performance of IONs in the human body.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!