Detection of large extracellular silver nanoparticle rings observed during mitosis using darkfield microscopy.

During studies on the absorption and interactions between silver nanoparticles and mammalian cells grown in vitro it was observed that large extracellular rings of silver nanoparticles were deposited on the microscope slide, many located near post-mitotic cells. Silver nanoparticles (AgNP, 80nm), coated with citrate, were incubated at concentrations of 0.3 to 30 μg/ml with a human-derived culture of retinal pigment epithelial cells (ARPE-19) and observed using darkfield and fluorescent microscopy, 24 h after treatment.

Biophysical comparison of four silver nanoparticles coatings using microscopy, hyperspectral imaging and flow cytometry.

This study compared the relative cellular uptake of 80 nm silver nanoparticles (AgNP) with four different coatings including: branched polyethyleneimine (bPEI), citrate (CIT), polyvinylpyrrolidone (PVP), and polyethylene glycol (PEG). A gold nanoparticle PVP was also compared to the silver nanoparticles. Biophysical parameters of cellular uptake and effects included flow cytometry side scatter (SSC) intensity, nuclear light scatter, cell cycle distributions, surface plasmonic resonance (SPR), fluorescence microscopy of mitochondrial gross structure, and darkfield hyperspectral imaging.

Determination of Silver Nanoparticle Dose .

An important issue for interpreting nanomaterial testing is quantifying the dose delivered to target cells. Considerations include the concentration added to the culture, the proportion of the applied dose that interacts with the target cells, and the amount that is eventually absorbed by the target cells. Rapid and efficient techniques are needed to determine delivered doses.

In vitro screening of silver nanoparticles and ionic silver using neural networks yields differential effects on spontaneous activity and pharmacological responses.

Silver nanoparticles (AgNPs) are used in a wide range of consumer and medical products because of their antimicrobial and antifungal properties, and can translocate to the brain following exposure. Therefore, to screen AgNPs for potential impacts on human health, it is essential to examine neural function. The present study examined AgNPs (3 citrate coated, 3 PVP coated; 10-75nm) and AgNO3 effects on spontaneous and pharmacologically-induced neural network function in rat primary cortical cells on multi-well microelectrode array (mwMEA) plates.

Neurophysiological assessment of auditory, peripheral nerve, somatosensory, and visual system function after developmental exposure to gasoline, E15, and E85 vapors.

The use of gasolines blended with a range of ethanol concentrations may result in inhalation of vapors containing a variable combination of ethanol with other volatile gasoline constituents. The possibility of exposure and potential interactions between vapor constituents suggests the need to evaluate the possible risks of this complex mixture. Previously we evaluated the effects of developmental exposure to ethanol vapors on neurophysiological measures of sensory function as a component of a larger project evaluating developmental ethanol toxicity.

Characterization, detection, and counting of metal nanoparticles using flow cytometry.

There is a need to accurately detect, characterize, and quantify nanoparticles in suspensions. This study helps to understand the complex interactions between similar types of nanoparticles. Before initiating a study of metal nanoparticles, five submicron PS beads with sizes between 200 nm and 1 µm were used to derive a reference scale that was useful in evaluating the flow cytometer for functionality, sensitivity, resolution, and reproducibility.

In vitro screening of metal oxide nanoparticles for effects on neural function using cortical networks on microelectrode arrays.

Nanoparticles (NPs) may translocate to the brain following inhalation or oral exposures, yet higher throughput methods to screen NPs for potential neurotoxicity are lacking. The present study examined effects of 5 CeO2 (5- 1288 nm), and 4 TiO2 (6-142 nm) NPs and microparticles (MP) on network function in primary cultures of rat cortex on 12 well microelectrode array (MEA) plates. Particles were without cytotoxicity at concentrations ≤50 µg/ml.