Search

Nanomaterials are being extensively produced and applied in society. Human and environmental exposures are, therefore, inevitable and so increased attention is being given to nanotoxicity. While silica nanoparticles (NP) are one of the top five nanomaterials found in consumer and biomedical products, their toxicity profile is poorly characterized. In this study, we investigated the toxicity of silica nanoparticles with diameters 20, 50 and 80 nm using an in vivo zebrafish platform that analyzes multiple endpoints related to developmental, cardio-, hepato-, and neurotoxicity. Results show that except for an acceleration in hatching time and alterations in the behavior of zebrafish embryos/larvae, silica NPs did not elicit any developmental defects, nor any cardio- and hepatotoxicity. The behavioral alterations were consistent for both embryonic photomotor and larval locomotor response and were dependent on the concentration and the size of silica NPs. As embryos and larvae exhibited a normal touch response and early hatching did not affect larval locomotor response, the behavior changes observed are most likely the consequence of modified neuroactivity. Overall, our results suggest that silica NPs do not cause any developmental, cardio- or hepatotoxicity, but they pose a potential risk for the neurobehavioral system. ispartof: Scientific Reports vol:6 issue:1 ispartof: location:England status: published

Gold nanoparticles functionalized with polyethylene glycol of different chain lengths are used to determine the influence of the capping layer thickness on the radiosensitizing effect of the particles. The size variations in organic coating, built up with polyethylene glycol polymers of molecular weight 1-20 kDa, allow an evaluation of the decrease in dose enhancement percentages caused by the gold nanoparticles at different radial distances from their surface. With localized eradication of malignant cells as a primary focus, radiosensitization is most effective after internalization in the nucleus. For this reason, we performed controlled radiation experiments, with doses up to 20 Gy and particle diameters in a range of 5-30 nm, and studied the relaxation pattern of supercoiled DNA. Subsequent gel electrophoresis of the suspensions was performed to evaluate the molecular damage and consecutively quantify the gold nanoparticle sensitization. In conclusion, on average up to 58.4% of the radiosensitizing efficiency was lost when the radial dimensions of the functionalizing layer were increased from 4.1 to 15.3 nm. These results serve as an experimental supplement for biophysical simulations and demonstrate the influence of an important parameter in the development of nanomaterials for targeted therapies in cancer radiotherapy.

An optical flux sensor, based on the fluorescence properties of materials and nanoparticles, has been developed to control the deposition rate in thin film deposition systems. Using a simple diode laser and a photomultiplier tube with a light filter, we report the detection of gallium atoms and CdSe-ZnS quantum dots. This setup has a high sensitivity and reproducibility. received: 2015-12-24 accepted: 2016-06-30 published: 2016-07-20 ispartof: Review of Scientific Instruments vol:87 issue:7 ispartof: location:United States status: published

In microelectronics build-up technology interfaces are realized between a polymer and a metal. The peel force is a measure for the quality of the adhesion. To improve adhesion between epoxy and electrochemically deposited copper, the polymer is generally pretreated with wet-chemical sweller and oxidizing treatments. It was shown that peel force is strongly dependent on the pretreatment conditions. This paper concerns different sweller and oxidizer treatment times for the epoxy. Copper is deposited by an electroless/electrogalvanic plating process. Before Cu-deposition and after peel force measurements, the obtained surface of the epoxy and the Cu-strips are studied with XPS. Atomic percentages of O, C, N, Cu, Pd and Sn are measured and the spectra are deconvoluted. Based on these results confirmations are presented for the proposed pore development in epoxy polymers due to wet chemical treatments (sweller and oxidizer). Between the XPS-results, peel force and AFM roughness measurements, correlations are presented.